UNDERWRITING AGREEMENT

November 5, 2025

AltaGas Ltd.
1300, 707 – 5th Street S.W.
Calgary, Alberta T2P 1V8

Dear Sirs/Mesdames:

Re: Distribution of Common Shares of AltaGas Ltd.

CIBC World Markets Inc. ("CIBC"), TD Securities Inc. ("TD"), RBC Dominion Securities Inc. ("RBC") and Scotia Capital Inc. ("Scotia" and, together with CIBC, TD and RBC, the "Joint Bookrunners") and each of the other underwriters listed in Schedule A to this Agreement (each an "Underwriter" and collectively, the "Underwriters") understand that AltaGas Ltd. (the "Corporation") proposes to issue and sell 10,100,000 Common Shares (as defined below) (the "Firm Shares") at a price per Firm Share of $39.65 (the "Offering Price"). Upon and subject to the terms and conditions contained herein, the Underwriters hereby severally, and not jointly, in the respective percentages set forth in Schedule A attached hereto, agree to purchase from the Corporation and, by its acceptance thereof, the Corporation agrees to sell to the Underwriters, at the Closing Time (as defined below), all but not less than all of the Firm Shares for an aggregate purchase price of $400,465,000.

The Underwriters understand that the Corporation has prepared and, concurrently with or immediately after the execution thereof, will file the Prospectus Supplement (as defined below) and all necessary documents relating thereto and will take all additional steps to qualify the Offered Shares (as defined below) for Distribution in the Qualifying Jurisdictions (as defined below). The Underwriters intend to make a public offering of the Offered Shares in the Qualifying Jurisdictions and on a private placement basis in offshore jurisdictions outside of Canada and the United States (as defined below) upon the terms set forth herein and in the Prospectus, including that no offshore sale shall require the Corporation to make any filing in such jurisdiction or otherwise become subject to any ongoing reporting obligations. Furthermore, the Corporation understands that the Underwriters reserve the right to offer and resell the Offered Shares in the United States solely to Qualified Institutional Buyers (as defined below) pursuant to Rule 144A under the U.S. Securities Act. All offers and sales of the Offered Shares in the United States (a) will be made in accordance with Schedule B attached hereto (which schedule is incorporated into and forms part of this Agreement), (b) will be conducted in such a manner so as not to require registration thereof under the U.S. Securities Act, and (c) will be conducted through an affiliate of one or more of the Underwriters duly registered with the SEC (as defined below) and the Financial Industry Regulatory Authority, Inc. and in compliance with U.S. Securities Laws (as defined below). The Corporation acknowledges and agrees that the Underwriters may offer and sell the Offered Shares to or through any affiliates of the Underwriters and that any such affiliate may offer and sell the Offered Shares purchased by it.

The Corporation hereby grants to the Underwriters (in accordance with the percentages set forth in Schedule A) an over-allotment option (the "Over-Allotment Option"), for the purposes of covering over-allocations, if any, to purchase, severally and not jointly, and offer for re-sale pursuant hereto up to an aggregate of 1,515,000 additional Common Shares (the "Additional Shares" and, together with the Firm Shares, the "Offered Shares") at the Offering Price per Additional Share, being an aggregate purchase price of up to an additional $60,069,750 upon the terms and conditions set forth herein. The Over-Allotment Option may be exercised, in whole or in part, at any time and from time to time for a

period of 30 days from and including the Closing Date (as defined below) by the Joint Bookrunners, on behalf of the Underwriters, by giving written notice to the Corporation in accordance with Section 9(a).

In consideration of the agreement of the Underwriters to purchase the Firm Shares and, if applicable, the Additional Shares, and to offer such Offered Shares for re-sale to the public, the Corporation hereby agrees to pay or cause to be paid to the Underwriters at the Closing Time, an aggregate fee equal to 4.0% of the aggregate gross proceeds of the Distribution (as defined below), including any exercise of the Over-Allotment Option (collectively, the "Underwriting Fee").

In this Agreement, capitalized terms not otherwise defined herein shall have the following meanings:

"Agreement" means the agreement resulting from the acceptance by the Corporation of the offer made hereby, as the same may be supplemented, amended and/or restated from time to time;

"Amendment" has the meaning ascribed thereto in Section 4;

"Ancillary Documents" means any documents executed and delivered, or to be executed and delivered, by the Corporation in connection with the transactions contemplated by this Agreement;

"Base Shelf Prospectus" means the base shelf prospectus of the Corporation dated March 12, 2025 (in both the English and French languages unless the context indicates otherwise), including all documents incorporated by reference therein for purposes of the offering of the Offered Shares (unless the context indicates otherwise);

"Business Day" means a day which is not a Saturday, Sunday or statutory or civic holiday in Calgary, Alberta;

"Canadian Securities Regulators" means the applicable securities commission or securities regulatory authority in each of the Qualifying Jurisdictions;

"CBCA" means Canada Business Corporations Act;

"CDS" means CDS Clearing and Depository Services Inc.;

"CFPOA" means the Corruption of Foreign Public Officials Act (Canada);

"Closing Date" means November 7, 2025 or such other date as the Joint Bookrunners and the Corporation may agree upon in writing, but in any event not later than December 15, 2025;

"Closing Time" means 6:00 a.m. (Calgary time) on the Closing Date or such other time on the Closing Date as the Joint Bookrunners and the Corporation may agree upon;

"Common Shares" means common shares in the capital of the Corporation;

"comparables" has the meaning given to that term in NI 41-101;

"Distribution" means "distribution" or "distribution to the public", as those terms are defined by Securities Laws;

"Environmental Laws" means any applicable domestic or foreign, federal, provincial, state, local or municipal laws, statues, ordinances, by-laws and regulations and orders, directives and decisions

rendered by any ministry, department or administrative or regulatory agency relating to the protection of the environment, occupational health and safety or the processing, use, treatment, storage, disposal, discharge, transport or handling of any pollutants, contaminants, chemicals or industrial, toxic or hazardous substances or wastes;

"Environmental Permit" means any material licences, permits, approvals, consents, certificates, registrations and other authorizations required under all applicable Environmental Laws;

"Excluded Transaction" has the meaning ascribed thereto in Section 7(h);

"EY" means Ernst & Young LLP;

"FCPA" means U.S. Foreign Corrupt Practices Act of 1977, as amended, and the rules and regulations thereunder;

"Final Receipt" has the meaning ascribed thereto in Section 1(a);

"Financial Statements" means, collectively, the most recent audited annual comparative consolidated financial statements of the Corporation together with the notes thereto and the auditors' report thereon, and the most recent unaudited interim comparative consolidated financial statements of the Corporation together with the notes thereto, incorporated or deemed to be incorporated by reference in the Prospectus;

"Indemnified Party" has the meaning ascribed thereto in Section 11(a);

"Indemnifying Party" has the meaning ascribed thereto in Section 11(a);

"limited-use version" has the meaning given to that term in NI 41-101;

"Marketing Documents" means the investor presentation prepared for potential investors in connection with the offering of Offered Shares dated and filed on November 3, 2025 and the term sheet prepared for potential investors in connection with the offering of the Offered Shares dated and filed on November 3, 2025;

"marketing materials" has the meaning given to that term in NI 41-101;

"material" or "materially", when used in relation to the Corporation, means material in relation to the Corporation and its Subsidiaries taken as a whole;

"material change", "material fact" and "misrepresentation" have the meanings attributed thereto under Securities Laws;

"Material Subsidiaries" means each of the Subsidiaries of the Corporation that represents at least 10% of the consolidated revenues and consolidated assets of the Corporation and its Subsidiaries taken as a whole, in each case as of the date of the most recent audited financial statements of the Corporation incorporated by reference in the Prospectus;

"MI 11-102" means Multilateral Instrument 11-102 – "Passport System" and its companion policy of the Canadian Securities Administrators (other than Ontario), as amended or replaced;

"Money Laundering Laws" has the meaning ascribed thereto in Section 6(gg);

"NI 41-101" means National Instrument 41-101 – "General Prospectus Requirements" of the Canadian Securities Administrators, as amended or replaced;

"NI 44-101" means National Instrument 44-101 – "Short Form Prospectus Distributions" of the Canadian Securities Administrators, as amended or replaced;

"NI 44-102" means National Instrument 44-102 – "Shelf Distributions" of the Canadian Securities Administrators, as amended or replaced;

"NI 52-109" means national Instrument 52-109 – "Certification of Disclosure in Issuers' Annual and Interim Filings";

"NP 11-202" means National Policy 11-202 – "Process for Prospectus Reviews in Multiple Jurisdictions" of the Canadian Securities Administrators, as amended or replaced;

"OFAC" means the Office of Foreign Assets Control of the U.S. Treasury Department;

"Over-Allotment Option Closing Date" means the date(s) on which the Additional Shares are to be purchased, but in each case not later than 30 days after the Closing Date;

"Over-Allotment Option Closing Time" means 6:00 a.m. (Calgary time) on the Over-Allotment Option Closing Date, or such other time on the Over-Allotment Option Closing Date as the Joint Bookrunners and the Corporation may agree upon;

"Over-Allotment Option Notice" has the meaning ascribed thereto in Section 9(a);

"Passport System" means the system and procedures for prospectus filing and review in one or more Canadian jurisdiction pursuant to MI 11-102 and NP 11-202;

"Preferred Shares" means preferred shares in the capital of the Corporation;

"Prospectus" means, collectively, the Base Shelf Prospectus and the Prospectus Supplement, in the English and French languages, including the documents incorporated or deemed to be incorporated therein by reference, as further supplemented or amended from time to time;

"Prospectus Supplement" means the shelf prospectus supplement of the Corporation in the English and French languages, incorporated or deemed to be incorporated by reference in the Base Shelf Prospectus for purposes of the Distribution of the Offered Shares in the Qualifying Jurisdictions as contemplated by NI 44-102 which shall include all documents incorporated by or deemed to be incorporated by reference therein;

"provide", in the context of sending or making available marketing materials to a potential investor of Offered Shares, has the meaning given to that term under Securities Laws;

"Public Record" means all information and documents filed by the Corporation on SEDAR+ with the applicable Canadian Securities Regulators in compliance or purported compliance with Securities Laws;

"Qualifying Jurisdictions" means, collectively, each of the provinces of Canada;

"SEC" means the United States Securities Exchange Commission;

"Securities Laws" means, collectively, the TSX and all applicable securities commission or securities regulatory authority in each of the Selling Jurisdictions;

"SEDAR+" means the computer system for the transmission, receipt, acceptance, review and dissemination of documents filed in electronic format known as the System for Electronic Data Analysis and Retrieval+;

"Selling Firms" has the meaning ascribed thereto in Section 2(a);

"Selling Jurisdictions" means, collectively, all of the Qualifying Jurisdictions, the United States and such other jurisdictions outside of Canada and the United States as the Corporation and the Underwriters may agree;

"Shelf Procedures" means the rules and procedures established pursuant to NI 44-102 and the WKSI Blanket Orders;

"Subsidiary" means a "subsidiary" of the Corporation within the meaning given to that term pursuant to the provisions of the Securities Act (Alberta);

"template version" has the meaning ascribed thereto under NI 41-101 and includes any revised template version of marketing materials as contemplated by NI 41-101;

"TMX Group" has the meaning ascribed thereto in Section 30;

"Transfer Agent" means Computershare Trust Company of Canada, the registrar and transfer agent for the Common Shares;

"TSX" means the Toronto Stock Exchange;

"United States" means the United States of America, its territories and possessions, any state of the United States and the District of Columbia;

"U.S. Exchange Act" means the United States Securities Exchange Act of 1934, as amended;

"U.S. Placement Memorandum" means the U.S. placement memorandum, in a form satisfactory to the Underwriters and the Corporation, each acting reasonably, which will be attached to the Prospectus, to be delivered to each offeree in the United States in accordance with Schedule B attached hereto;

"U.S. Securities Act" means the United States Securities Act of 1933, as amended;

"U.S. Securities Laws" means all applicable securities legislation in the United States, including the U.S. Securities Act, the U.S. Exchange Act and the rules and regulations promulgated thereunder, and any applicable state securities laws;

"WKSI Blanket Orders" means, collectively, Alberta Securities Commission Blanket Order 44-501 Re Exemption from Certain Prospectus Requirements for Well-Known Seasoned Issuers, as varied by the Alberta Securities Commission's Variation of Blanket Order 44-501 and the equivalent local blanket orders (as amended, modified or varied) of the Canadian Securities Regulators referred to in CSA Staff Notice 44-306 – Blanket Orders Exempting Well-known Seasoned Issuers from Certain Prospectus Requirements.

Any reference in this Agreement to a Section number shall refer to a section of this Agreement.

TERMS AND CONDITIONS

1. Qualification of Offered Shares

(a) The Corporation represents and warrants to and for the benefit of the Underwriters that it has elected to rely upon the Shelf Procedures, has prepared and filed the Base Shelf Prospectus (in English and French) and all such other documents as are required under applicable Securities Laws (in English and, as required, in French), utilizing the Passport System and has obtained a final receipt dated March 12, 2025 in respect of the Base Shelf Prospectus evidencing that final receipts of the Canadian Securities Regulators have been issued or deemed to be issued (the "Final Receipt").

(b) The Corporation shall fulfil all legal requirements to be fulfilled by it to enable the Offered Shares to be offered for sale by the Corporation and sold to the public in each of the Qualifying Jurisdictions by or through the Underwriters and other investment dealers and brokers who comply with Securities Laws. All legal requirements to enable the Distribution of the Offered Shares that are the responsibility of the Corporation shall be fulfilled by the Corporation as soon as practicable. Without limiting the generality of the foregoing, the Corporation shall as soon as possible on November 5, 2025 (or such other date as the Corporation and the Underwriters may agree) prepare and file the Prospectus Supplement on SEDAR+ in each of the Qualifying Jurisdictions and will promptly take all other steps and proceedings that may be necessary in order to qualify the Offered Shares for Distribution in the Qualifying Jurisdictions or, in the event that the Offered Shares have, for any reason, ceased to so qualify, to again qualify the Offered Shares for Distribution, and shall provide the Prospectus Supplement in compliance with Section 3(a).

(i) the Corporation shall prepare, in consultation with the Joint Bookrunners, and approve in writing, prior to such time any marketing materials are provided to potential investors in Offered Shares, a template version of any marketing materials reasonably requested to be provided by the Underwriters to any such potential investor, such marketing materials to comply with Securities Laws and to be acceptable in form and substance to the Underwriters and their counsel, acting reasonably;

(ii) the Joint Bookrunners shall, on behalf of the Underwriters, approve a template version of any such marketing materials in writing prior to such time such marketing materials are provided to potential investors in Offered Shares; and

(iii) the Corporation shall file a template version of the English version of any such marketing materials on SEDAR+ as soon as reasonably practical after such marketing materials are so approved in writing by the Corporation and the Joint Bookrunners, on behalf of the Underwriters, and in any event on or before the day the marketing materials are first provided to any potential investor in Offered Shares, and any comparables shall be removed from the template version in accordance with NI 44-102 prior to filing such on SEDAR+ (provided that if any such comparables are removed, the Corporation shall deliver a complete template version of any such marketing materials to the Canadian Securities Regulators), and the Corporation shall provide a copy of such filed template version to the

Underwriters as soon as practicable following such filing. Unless otherwise agreed to by the Underwriters, the French language version of any such marketing materials shall be filed on SEDAR+ prior to or concurrently with the filing of the Prospectus Supplement as contemplated herein and a copy thereof shall be delivered to the Underwriters as soon as practicable following such filing; and

(iv) following the approvals set forth in Sections 1(c)(i) to (iii), the Underwriters may provide a limited-use version of such marketing materials to potential investors in Offered Shares in accordance with Securities Laws.

(d) The Corporation and each Underwriter, on a several basis, covenants and agrees not to provide any potential investor of Offered Shares with any marketing materials except for marketing materials which have been approved as contemplated in Section 1(c), and then only to potential investors in the Qualifying Jurisdictions.

Distribution of Offered Shares

(a) The Underwriters will offer the Offered Shares for sale to the public in the Qualifying Jurisdictions, directly and through other investment dealers and brokers (the Underwriters, together with such other investment dealers and brokers, the "Selling Firms" or each a "Selling Firm") only as permitted by Securities Laws and upon the terms and conditions set forth in the Prospectus and this Agreement. The Underwriters agree to sell the Offered Shares only in accordance with, and in a manner permitted by, the laws of each of the Qualifying Jurisdictions and to require each Selling Firm to agree with the Underwriters to so sell the Offered Shares. For purposes of this Section 2, the Underwriters shall be entitled to assume that the Offered Shares are qualified for Distribution in any Province of Canada where the Final Receipt was obtained from the applicable Canadian Securities Regulator unless notice to the contrary from the Corporation or the applicable Canadian Securities Regulator is provided to the Underwriters. Notwithstanding the foregoing provisions of this Section 2, an Underwriter will not be liable under this Section 2 with respect to a default under this Section 2 by another Underwriter or Selling Firm.

(b) The Underwriters shall use their reasonable commercial efforts to complete and cause the Selling Firms to complete the Distribution of the Offered Shares as promptly as possible, and shall give prompt notice to the Corporation when, in the opinion of the Underwriters, such Distribution has been completed and shall give notice to the Corporation of the proceeds realized in each Qualifying Jurisdiction from the Distribution of the Offered Shares. The Underwriters may solicit offers to purchase or sell the Offered Shares outside of Canada in accordance with applicable law, but will not solicit offers to purchase or sell the Offered Shares so as to require registration of the Offered Shares or the filing of a prospectus or registration statement with respect to the Distribution of the Offered Shares under the laws of such jurisdiction (and will require each Selling Firm to agree with the Underwriters not to so solicit or sell).

(c) The Corporation shall co-operate in all respects with the Underwriters to allow and assist the Underwriters to participate fully in the preparation of the Prospectus Supplement, any Amendment thereto and any marketing materials and shall allow the Underwriters and their counsel to conduct all "due diligence" investigations which the Underwriters may reasonably require to fulfill the Underwriters' obligations as

underwriters and to enable the Underwriters to execute any certificate required to be executed by the Underwriters in such documentation.

(d) The Underwriters may offer the Offered Shares at a price less than the Offering Price per Offered Share in compliance with Securities Laws and, specifically in the case of any Offered Shares offered in the Qualifying Jurisdictions, the requirements of NI 44-101 and the disclosure concerning the same which is contained in the Prospectus. Notwithstanding any such reduction in the purchase price below the Offering Price per Offered Share hereunder, the Corporation will still receive a price equal to the Offering Price per Offered Share.

Documents to be Delivered by the Corporation

(a) Delivery of the Prospectus Supplement and any supplementary materials will be satisfied in accordance with the "access equals delivery" provisions contained in Part 6A of NI 44-102 and the Underwriters and the Corporation shall satisfy any request for electronic or paper copies of the Prospectus in accordance with the requirements of NI 44-102, without charge.

(b) The Corporation shall deliver to the Underwriters:

(i) prior to the filing of the Prospectus Supplement, a copy of the Base Shelf Prospectus signed by or on behalf of the Corporation as required by the laws of the Qualifying Jurisdictions;

(ii) on the date of filing of the Prospectus Supplement, a copy of the Prospectus Supplement signed by or on behalf of the Corporation as required by the laws of the Qualifying Jurisdictions, as applicable;

(iii) the U.S. Placement Memorandum prepared for delivery to purchasers under the Distribution resident in, or otherwise subject to the laws of, the United States and purchasing Offered Shares pursuant to Rule 144A under the U.S. Securities Act, such U.S. Placement Memorandum to be in form and substance satisfactory to the Corporation and the Joint Bookrunners, on behalf of the Underwriters, acting reasonably;

(iv) on or prior to the date of filing of any Amendment, copies of the Amendment signed by or on behalf of the Corporation as required by the laws of the Qualifying Jurisdictions, as applicable;

(v) at the time of the delivery to the Underwriters pursuant to this Section 3 of copies of the Prospectus, the Prospectus Supplement, any Amendment, and any marketing materials pursuant to Section 1(c), in each case in the French language:

A. opinions of Quebec counsel to the Corporation dated the date of such document and stating that, except for any financial statements and financial information (including without limitation the Financial Statements and the notes to any financial statements and auditors' reports thereon, as applicable) which are the subject of the opinions of the auditors referred to in Sections 3(b)(v)B, contained or incorporated

by reference in such document, the document in the French language is in all material respects a complete and accurate translation of the document in the English language; and

B. an opinion of EY, the auditors of the Corporation dated the date of such document and stating that any financial statements and financial information (including without limitation the Financial Statements and the notes to any financial statements and auditors' reports thereon, as applicable) pertaining to the Corporation, together with all pro forma financial statements and financial information (including any explanatory notes and the notes to any such pro forma financial statements) contained or incorporated by reference in such document in the French language is in all material respects a complete and proper translation of such financial statements and financial information contained or incorporated by reference therein in the English language;

(vi) at or prior to the filing of the Prospectus Supplement: a comfort letter dated the date of the Prospectus Supplement from EY, the auditors of the Corporation, acceptable in form and substance to the Underwriters, acting reasonably, with respect to the financial and accounting information relating to the Corporation contained in or incorporated by reference in the Prospectus based on a review by EY having a cut-off date not more than two Business Days prior to the date of the comfort letter; and

(c) During the period of Distribution of the Offered Shares, the Corporation will promptly provide to the Underwriters, for review and comment by the Underwriters and the Underwriters' counsel, prior to filing or issuance:

(i) any financial statement of the Corporation;

(ii) any proposed document, including without limitation any amendment to or new annual information form, material change report, interim report, business acquisition report, or information circular, which may be incorporated, or deemed to be incorporated, by reference in the Prospectus; and

(iii) any press release of the Corporation.

(d) The Corporation shall also prepare and deliver promptly to the Underwriters signed copies, as applicable, of any Amendment required to be filed or delivered by the Corporation in compliance with applicable Securities Laws.

(e) Delivery of the Prospectus by the Corporation shall constitute the representation and warranty of the Corporation to the Underwriters that, as at the respective date of filing or delivery of such document:

(i) all information and statements (except information and statements relating solely to the Underwriters and provided by the Underwriters in writing) contained in such Prospectus are true and correct, in all material respects, and contain no misrepresentation and constitute full, true and plain disclosure of all material facts relating to the Corporation, the Distribution and the Offered Shares;

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(ii) no material fact or information has been omitted therefrom (except facts or information relating solely to the Underwriters) which is required to be stated in such Prospectus or is necessary to make the statements or information contained in such Prospectus not misleading in light of the circumstances under which they were made; and

(iii) except with respect to any information relating solely to the Underwriters and provided by the Underwriters in writing, such Prospectus complies in all material respects with the requirements of applicable Securities Laws.

Such delivery shall also constitute the Corporation's consent to the Underwriters' use of the Prospectus in connection with the Distribution of the Offered Shares in the Selling Jurisdictions in compliance with applicable Securities Laws unless otherwise advised in writing.

Amendment

The Corporation shall deliver to the Underwriters duly signed copies of all amendments or supplements or any other supplemental documents to the Base Shelf Prospectus or the Prospectus Supplement, as the case may be, required to be prepared by the Corporation under Securities Laws, or to the documents incorporated or deemed to be incorporated therein by reference that relate to the offering of the Offered Shares in the Qualifying Jurisdictions (collectively, the "Amendment") or other documents required to be filed under Section 5. The Amendment shall be in form and substance satisfactory to the Underwriters, acting reasonably. Prior to the filing of any Amendment, the Corporation shall deliver to the Underwriters with respect to such Amendment, letters and opinions similar to those referred to in Sections 3(b)(v) and 3(b)(vi).

Material Changes

Commencing on the date hereof and until the completion of the Distribution of the Offered Shares, the Corporation shall promptly notify the Underwriters in writing of:

(a) any change (actual, anticipated, contemplated or threatened, financial or otherwise) in the business, affairs, operations, assets (including intangible assets), liabilities (contingent or otherwise), condition (financial or otherwise), cash flows, income, results of operations or capital of the Corporation and its Subsidiaries taken as a whole;

(b) any fact that has arisen or has been discovered which would have been required to have been stated or referred to in the Prospectus had the fact arisen or been discovered on, or prior to, the date of the Prospectus Supplement; and

which change or material fact is, or may be, of such a nature as:

(d) to render the Prospectus or any Amendment, as they exist taken together in their entirety immediately prior to such change or material fact, misleading or untrue in any material respect or would result in any of such documents, as they exist taken together in their entirety immediately prior to such change or material fact, containing a misrepresentation;

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(e) would result in the Prospectus or any Amendment, as they exist taken together in their entirety immediately prior to such change or material fact, not complying with laws of the Qualifying Jurisdictions; or

(f) would reasonably be expected to have a significant adverse effect on the market price or value of the Offered Shares.

The Corporation shall promptly, and in any event within any applicable time limitation, comply with all applicable filing and other requirements under Securities Laws arising as a result of such fact or change provided that the Corporation shall not file any Amendment or other document without first consulting with the Underwriters as to the form and content thereof. The Corporation shall, in good faith, discuss with the Underwriters any fact or change (actual, anticipated, contemplated or threatened, financial or otherwise) which is of such a nature that there is any doubt as to whether notice in writing need be given to the Underwriters pursuant to this Section 5 and, in any event, prior to making any filing referred to in this Section 5.

In addition, if, prior to the completion of the Distribution of the Offered Shares, there is any change in any Securities Laws which results in the requirement to file an Amendment, the Corporation shall, to the reasonable satisfaction of the Underwriters' counsel in the applicable jurisdictions, make any such filing required as soon as possible.

If a material change or a change in a material fact occurs prior to the Closing Date, then, subject to Section 14, the Closing Date shall be, unless the Corporation and the Underwriters otherwise agree in writing, the sixth Business Day following the date on which all applicable filings or other requirements of Securities Laws with respect to such material change or change in a material fact have been complied with in all Qualifying Jurisdictions and any appropriate Passport System receipt obtained for such filings and notice of such filings have been received by the Underwriters; provided, however, without the consent of the Underwriters, in no event shall the Closing Date be later than December 15, 2025.

Representations, Warranties and Covenants of the Corporation

The delivery to the Underwriters of the documents referred to in Section 1(c) and Sections 3(b)(i), (ii) and (iii) shall constitute the consent of the Corporation to the use by the Underwriters and the Selling Firms of such documents in connection with the Distribution of the Offered Shares in compliance with the provisions of this Agreement and shall constitute representations, warranties and covenants, as applicable, to the Underwriters by the Corporation that:

(a) the Prospectus and the Prospectus Supplement each complies (and when filed each Amendment will comply) with the provisions of applicable Securities Laws, including the Shelf Procedures (except for any information contained therein relating solely to the Underwriters and provided by the Underwriters, or counsel to the Underwriters, in writing expressly for inclusion therein);

(b) this Agreement and the Ancillary Documents shall upon execution be valid and binding obligations of the Corporation enforceable in accordance with their respective terms, except as the enforceability thereof may be limited by (i) bankruptcy, insolvency, reorganization, moratorium or similar laws affecting creditors' rights generally, (ii) general equitable principles, or (iii) limitations under applicable laws in respect of rights of indemnity, contribution and waiver of contribution;

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(c) each of the Prospectus and the execution and filing of the Prospectus with the Canadian Securities Regulators have been or will be prior to the filing or use thereof duly approved and authorized by all necessary action by the Corporation, and the Prospectus will be duly executed by and filed on behalf of the Corporation;

(d) the attributes of the Offered Shares will conform in all material respects with the description thereof in the Prospectus, this Agreement and the Ancillary Documents, as applicable;

(e) all necessary corporate action has been taken by the Corporation so as to (i) authorize the execution, delivery and performance of this Agreement and the Ancillary Documents; and (ii) validly issue and sell the Offered Shares;

(f) the Offered Shares will be qualified investments under the Income Tax Act (Canada) for a trust governed by a registered retirement savings plan, a registered education savings plan, a registered retirement income fund, a deferred profit sharing plan, a registered disability savings plan, a first home savings account, and a tax-free savings account, as described and subject to the qualifications set forth in the Prospectus;

(g) the form of the certificate representing the Offered Shares has been duly approved by the directors of the Corporation and complies with the provisions of the CBCA and, to the extent applicable, the rules and policies of the TSX;

(h) there is no person acting at the request of the Corporation, other than the Underwriters, who is entitled to any brokerage, agency or similar fee in connection with the transactions contemplated herein;

(i) other than the Corporation (and the Underwriters in respect of the Underwriting Fee and the Underwriters' expenses), there is no person that is or will be entitled to the proceeds of the Distribution under the terms of any contract or commitment (written or oral), or other instrument or document;

(j) subject to the filing of the Prospectus Supplement and any other documents required to be filed with the Prospectus Supplement (including any template version of marketing materials), which the Corporation will file within the time limits prescribed in NI 44-102, the Corporation has fulfilled all requirements to be fulfilled by it, including the filing of the Prospectus and all continuous disclosure materials required to be filed pursuant to applicable Securities Laws to enable the Offered Shares to be offered for sale and sold to the public in all of the Selling Jurisdictions through registrants who have complied with the relevant provisions of applicable Securities Laws and the terms and conditions of their registration;

(k) the issuance of the Offered Shares will not result in a breach of, a default under or the creation of any lien on its or any of its Material Subsidiaries' properties under any agreement or instrument to which it or any of its Material Subsidiaries is a party or by which its or any of its Material Subsidiaries' property and assets are bound or affected, save and except where such breach, default or lien will not have a material adverse effect on the business, operations, capital or conditions of the Corporation;

(l) except as disclosed in the Prospectus or any Amendment, there has been no material adverse change, financial or otherwise, in the business, affairs, operations, assets,

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liabilities (contingent or otherwise) or capital of the Corporation and its Subsidiaries, taken as a whole, since the end of the last completed fiscal year of the Corporation for which Financial Statements have been reported on by the auditors of the Corporation and filed with the Canadian Securities Regulators;

(m) the information and statements set forth in the Public Record were true, correct and complete and did not contain any misrepresentation, as at the date of such information or statements and the Corporation has not filed any confidential material change reports still maintained on a confidential basis and there are no undisclosed material facts with respect to the Corporation or the Offered Shares;

(n) the Corporation has been duly amalgamated and is a valid corporation existing under the CBCA, with all necessary corporate power and authority to (i) own and lease its properties and to conduct its business as described in the Prospectus, (ii) issue the Offered Shares, and (iii) enter into this Agreement and to perform its obligations hereunder and thereunder and to execute and deliver all other necessary documents in connection with the offering of the Offered Shares, including the Prospectus. All necessary action has been taken by the Corporation to execute and deliver this Agreement, the Prospectus and any marketing materials and to file such documents as required by applicable Securities Laws with the Canadian Securities Regulators;

(o) each Material Subsidiary is validly existing as a corporation, limited liability company, partnership or trust, as applicable, under the laws of its jurisdiction of incorporation or formation, as the case may be, with all necessary power and authority to own and lease its properties and to conduct its business as described in the Prospectus;

(p) other than pursuant to the credit facilities of the Corporation and its Subsidiaries, as disclosed in the Prospectus and any Amendment and subject to applicable laws, none of the Corporation or any of its Subsidiaries is currently prohibited, directly or indirectly, from paying dividends, from making distributions on its capital stock and other securities, or from paying interest or repaying any loans, notes, advances or other indebtedness of the Corporation or any of its Subsidiaries;

(q) the Corporation is not in default of any material requirement of applicable Securities Laws, no order ceasing or suspending trading in any securities of the Corporation or prohibiting the sale of the Offered Shares has been issued by any competent authority having jurisdiction and remains in effect and, to the knowledge of the Corporation, no proceedings for such purpose are pending, threatened or contemplated;

(r) the description of the assets and liabilities of the Corporation and its Subsidiaries (taken as a whole) set forth in the Financial Statements fairly presents, in accordance with United States generally accepted accounting principles consistently applied, the financial position and condition of the Corporation and its Subsidiaries (taken as a whole) as at the dates thereof and reflects all material liabilities (absolute, accrued, contingent or otherwise) of the Corporation and its Subsidiaries (taken as a whole), as at the dates thereof;

(s) to the knowledge of the Corporation, no current or former officer, director, employee, consultant or security holder of the Corporation has any cause of action or other claim whatsoever against, or owes any amount to, the Corporation, except for claims in the

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ordinary and normal course of the business such as for accrued vacation pay or other amounts or matters which would not be material to the Corporation taken as a whole;

(t) other than as disclosed in the annual information form of the Corporation for the year ended December 31, 2024, to the knowledge of the Corporation, none of the current directors or officers of the Corporation are now, or have ever been (i) subject to an order or ruling of any securities regulatory authority or stock exchange prohibiting such individual from acting as a director or officer of a company; or (ii) subject to an order preventing, ceasing or suspending trading in any securities of the Corporation or other public company;

(u) all necessary documents and proceedings have been or will be filed and taken and all other legal requirements have been or will be fulfilled under each of the applicable Securities Laws in connection with the issuance and sale of the Offered Shares;

(v) EY are independent chartered professional accountants with respect to the Corporation within the meaning of the relevant rules and related interpretations prescribed by the relevant professional bodies in Canada and any applicable legislation or regulations;

(w) the Corporation and each of its Subsidiaries are insured by insurers of recognized financial responsibility against such losses and risks and in such amounts as the Corporation believes are prudent and customary for the businesses in which they are engaged; all policies of insurance and fidelity or surety bonds insuring the Corporation or any of its Subsidiaries or their respective businesses, assets, employees, officers and directors are in full force and effect, except where the failure to be in full force and effect would not reasonably be expected to have a material adverse effect on the Corporation and its Subsidiaries (taken as a whole); the Corporation and its Subsidiaries are in compliance with the terms of such policies and instruments in all material respects, except where such noncompliance would not reasonably be expected to have a material adverse effect on the Corporation and its Subsidiaries (taken as a whole); neither the Corporation nor any such Subsidiary has been refused any insurance coverage sought or applied for, except where such refusal would not reasonably be expected to have a material adverse effect; and neither the Corporation nor any such Subsidiary has received written notice of non-renewal of any material policy of the Corporation or any Subsidiary except in those situations where the Corporation believes it will be able to obtain similar coverage from similar insurers at market rates;

(x) all of the ownership interests in the Subsidiaries of the Corporation are directly or indirectly, legally and beneficially owned by the Corporation, in each case, free and clear of any liens, pledges, charges, encumbrances, security interests or other adverse claims whatsoever (except for certain security granted by Subsidiaries of the Corporation in favour of its lenders);

(y) except as shall have been made or obtained on or before the Closing Date, as of the Closing Date, no consent, approval, authorization, registration or qualification of any court, governmental agency or body, regulatory authority or contractual party shall be required for: (i) the Distribution of the Offered Shares; or (ii) the consummation of the transactions contemplated in this Agreement;

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(z) all authorizations, orders, permits, filings, licences, clearances, approvals and consents to be obtained by the Corporation under applicable laws, or under any agreements or documents by which the Corporation is bound, for the execution and delivery of this Agreement, and the failure of which to obtain would have a material adverse impact on the Corporation, have been obtained and are in full force, and this Agreement is a legal, valid and binding agreement of the Corporation, enforceable in accordance with its terms, subject as to enforcement to bankruptcy, insolvency, reorganization and other laws of general applicability relating to or affecting creditors' rights and to general principles of equity;

(aa) neither the Corporation nor any Subsidiary is in default or in breach of, and each of the execution and delivery of this Agreement and the Ancillary Documents, the performance by the Corporation and compliance with the terms of this Agreement and the Ancillary Documents, the issue, sale and delivery of the Offered Shares by the Corporation will not result in any breach of, or be in conflict with or constitute a default under, or create a state of facts which, after notice or lapse of time, or both, would constitute a default under any term or provision of the constating documents, articles, by-laws or resolutions (of the directors, committees of the directors and shareholders) of the Corporation or any Subsidiary, any mortgage, note, indenture, contract, agreement, instrument, lease or other document to which the Corporation or any Subsidiary, individually, is a party or by which any of them is bound or any judgment, decree, order, statute, rule or regulation applicable to the Corporation or any Subsidiary;

(bb) there are no legal or governmental actions, suits, proceedings, investigations or inquiries pending or, to the knowledge of the Corporation, contemplated or threatened against or affecting the Corporation or any of its Subsidiaries at law or in equity or before or by any federal, provincial, municipal or other governmental or regulatory department, commission, board, bureau, agency or instrumentality, foreign or domestic, which materially adversely affect, or are reasonably likely to materially adversely affect, the business, operations or condition of the Corporation or any of its Subsidiaries taken as a whole or which materially adversely affect, or are reasonably likely to materially adversely affect the Distribution of the Offered Shares or the validity of any action taken or to be taken by the Corporation hereunder or under any agreement contemplated hereby;

(cc) except as disclosed in the Prospectus and any Amendment, the Corporation and each of its Subsidiaries maintain a system of internal control over financial reporting that complies in all material respects with the requirements of NI 52-109 and a system of internal accounting controls sufficient to provide reasonable assurance that: (i) transactions are executed in accordance with management's general or specific authorizations; (ii) transactions are recorded as necessary to permit preparation of financial statements in conformity with United States generally accepted accounting principles and to maintain asset accountability; (iii) access to assets is permitted only in accordance with management's general or specific authorization; and (iv) the recorded accountability for assets is compared with the existing assets at reasonable intervals and appropriate action is taken with respect to any differences, except where the failure to maintain such a system would not reasonably be expected to have a material adverse effect on the Corporation and its Subsidiaries (taken as a whole); management of the Corporation has assessed the effectiveness of the Corporation's internal control over

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financial reporting, as at December 31, 2024, and has concluded that such internal control over financial reporting was effective as of such date;

(dd) except as disclosed in the Prospectus and any Amendment, the Corporation maintains disclosure controls and procedures that comply with the requirements of NI 52-109; such disclosure controls and procedures have been designed to ensure that information required to be disclosed by the Corporation in the reports that it files or submits under Securities Laws is recorded, processed, summarized and reported within the time periods specified in such securities laws; such disclosure controls and procedures were effective as of December 31, 2024 at a reasonable assurance level;

(ee) the Corporation and each of its Material Subsidiaries have good and marketable title to all real property and good title to all personal property owned by them which is material to the business of the Corporation and its Material Subsidiaries (taken as a whole), in each case free and clear of all liens, encumbrances and defects, except: (i) such as are described in the Prospectus and any Amendment, as the case may be; or (ii) such as are not material in amount or do not in the aggregate materially interfere with the use made and proposed to be made of such properties by the Corporation and its Material Subsidiaries; and any material real property and buildings held under lease by the Corporation and its Subsidiaries are held by them under valid, subsisting and enforceable leases and do not interfere with the use made and proposed to be made of such property and buildings by the Corporation and its Material Subsidiaries, in each case except as described in the Prospectus and any Amendment, as the case may be;

(ff) neither the Corporation nor any of Subsidiaries nor, to the knowledge of the Corporation, any director, officer, agent, employee or affiliate of the Corporation or any of its Subsidiaries is aware of or has taken any action, directly or indirectly, that would reasonably be expected to result in a material violation by such persons of the FCPA or the CFPOA including, without limitation, making use of the mails or any means or instrumentality of interstate commerce corruptly in furtherance of an offer, payment, promise to pay or authorization of the payment of any money, or other property, gift, promise to give, or authorization of the giving of anything of value to any "foreign official" (as such term is defined in the FCPA) or any foreign political party or official thereof or any candidate for foreign political office, in contravention of the FCPA; the Corporation, its Subsidiaries and, to the knowledge of the Corporation, its affiliates have conducted their businesses in material compliance with the FCPA and the CFPOA and have instituted and maintain policies and procedures designed to ensure, and which are reasonably expected to continue to ensure, continued compliance therewith;

(gg) the operations of the Corporation and its Subsidiaries are and have been conducted at all times in material compliance with applicable financial recordkeeping and reporting requirements and the money laundering statutes and the rules and regulations thereunder and any related or similar rules, regulations or guidelines, issued, administered or enforced by any governmental agency (collectively, the "Money Laundering Laws") and no action, suit or proceeding by or before any court or governmental agency, authority or body or any arbitrator involving the Corporation or any of its Subsidiaries with respect to the Money Laundering Laws is pending or, to the best knowledge of the Corporation, threatened;

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(hh) neither the Corporation nor any of its Subsidiaries nor, to the knowledge of the Corporation, any director, officer, agent, employee or affiliate of the Corporation or any of its Subsidiaries is currently subject to any sanctions administered by the OFAC, including sanctions with respect to Russia, Crimea, Ukraine, Russian persons or Ukrainian persons; and the Corporation will not directly or indirectly use the proceeds of the Distribution, or lend, contribute or otherwise make available such proceeds to any Subsidiary, joint venture partner or other person or entity, for the purpose of financing the activities of any person currently subject to any U.S. sanctions administered by OFAC, including sanctions with respect to Russia, Crimea, Ukraine, Russian persons or Ukrainian persons;

(ii) except to the extent that any violation or other matter referred to in this subsection does not have a material adverse effect on the business, financial conditions, assets, properties, liabilities or operations of the Corporation and its Subsidiaries (taken as a whole) or except as disclosed in the Prospectus and any Amendment, as the case may be:

(i) each of the Corporation and its Subsidiaries is in compliance with all applicable Environmental Laws, other than any non-compliance which would, individually or in the aggregate, not have a material adverse effect on the Corporation and its Subsidiaries, on a consolidated basis;

(ii) there has not occurred any material spills, emissions or pollution on any property of the Corporation or its Subsidiaries or for which the Corporation or any of its Subsidiaries is or may be responsible, nor is the Corporation or any of its Subsidiaries subject to any outstanding stop orders, control orders, clean-up orders or reclamation orders under Environmental Laws;

(iii) each of the Corporation and its Subsidiaries has obtained all Environmental Permits necessary for the operation of the businesses carried on by the Corporation and its Subsidiaries and each Environmental Permit is valid, subsisting and in good standing and none of the Corporation or its Subsidiaries is in material default or breach of any Environmental Permit and no proceeding is pending or, to the knowledge of the Corporation, contemplated or threatened to revoke or limit any Environmental Permit; and

(iv) except to the extent that such taxes are currently being contested in good faith by the Corporation, the Corporation and its Subsidiaries have paid, or made provision in their accounts in respect of, in all material respects, any and all liabilities for taxes, instalment of taxes, interest, penalties or other amounts payable by law to any relevant taxing authority in respect of all taxation years or reporting periods of the Corporation and its Subsidiaries, respectively, ending on or before the date hereof, and all of such payments shall, in all material respects, accurately reflect the aggregate liability of the Corporation and its Subsidiaries to such taxing authorities for such taxation years or reporting periods;

(jj) with such exceptions as are not material to the Corporation and its Subsidiaries (taken as a whole), the Corporation and each of its Subsidiaries has duly and on a timely basis filed all tax returns required to be filed by it, has paid all taxes due and payable by it and has paid all assessments and reassessments and all other taxes, governmental charges, penalties, interest and other fines due and payable by it and which were

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claimed by any governmental authority to be due and owing and adequate provision has been made for taxes payable for any completed fiscal period or reporting period for which tax returns are not yet required, there are no agreements, waivers, or other arrangements providing for an extension of time with respect to the filing of any tax return or payment of any tax, governmental charge or deficiency by the Corporation or any of its Subsidiaries and, to the knowledge of the Corporation, there are no actions, suits, proceedings, investigations or claims threatened or pending against any of the Corporation or its Subsidiaries in respect of taxes, governmental charges or assessments asserted by any such authority, and each of the Corporation and its Subsidiaries has withheld and remitted on a timely basis any amounts that it is required to withhold and remit under any applicable legislation;

(kk) except as disclosed in the Public Record, no material acquisitions or dispositions have been made by the Corporation or its predecessors or any of its Subsidiaries in the three most recently completed fiscal years, and neither the Corporation nor any of its Subsidiaries is party to any contract with respect to any transaction that constitutes or would constitute a "significant acquisition" or a "significant probable acquisition", in each case that would require disclosure in the Prospectus under Securities Laws;

(II) the information available on the Corporation's SEDAR+ profile is accurate and complete on the date of filing such information and such information does not contain a misrepresentation;

(mm) with respect to forward-looking information contained in the Public Record and the Prospectus:

(i) the Corporation had a reasonable basis for the forward-looking information at the time the disclosure was made; and

(ii) all forward-looking information is identified as such, and all such documents and information caution users of forward-looking information that actual results may vary from the forward-looking information, identify material risk factors that could cause actual results to differ materially from the forward-looking information, and state the material factors or assumptions used to develop the forward-looking information;

(nn) the records and minute books of the Corporation and its Subsidiaries which have been made available to the Underwriters, or their counsel, for review contain, in all material respects, complete and accurate minutes of all relevant meetings and resolutions duly passed or confirmed;

(oo) the Corporation is a "reporting issuer" or has equivalent status in each of the Qualifying Jurisdictions within the meaning of applicable Securities Laws in such Qualifying Jurisdictions;

(pp) except as disclosed in or contemplated by the Prospectus, since December 31, 2024 the Corporation has not incurred, assumed or suffered any liability (absolute, accrued, contingent or otherwise), or entered into any transaction, which is or may be material to the Corporation and its Subsidiaries, taken as a whole, and is not in the ordinary course of business;

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(qq) the authorized capital of the Corporation consists of: 1) an unlimited number of Common Shares; and 2) Preferred Shares issuable in series and limited to such number of Preferred Shares issuable in series at any time as have aggregate voting rights either directly or on conversion or exchange that in the aggregate represent less than 50% of the voting rights attaching to the then issued and outstanding Common Shares, each having the rights, privileges, restrictions and conditions set forth in the articles of amalgamation of the Corporation dated January 1, 2025;

(rr) the issued and outstanding capital of the Corporation at the date of this Agreement consists of 299,486,164 Common Shares, 300,000 Series 2022-A Shares, 250,000 Series 2022-B Shares, 200,000 Series 2023-A Shares and 8,000,000 Series G Shares, all of which shares are validly issued as fully paid and non-assessable shares;

(ss) no person has any agreement or option or any right or privilege capable of becoming an agreement or option for the purchase of any unissued securities of the Corporation, other than as listed below as at the date of this Agreement: (i) the Offered Shares issuable pursuant to this Agreement; (ii) 963,864 Common Shares issuable pursuant to the exercise of options issued pursuant to the Option Plan; (iii) the Series H Shares issuable on conversion of the Series G Shares; and (iv) the Series G Shares issuable on conversion of the Series H Shares;

(tt) the Corporation has not withheld from the Underwriters any fact or information relating to the Corporation or to the Distribution that could reasonably be expected to be material to the Underwriters or a potential purchaser of Offered Shares; and

(uu) Computershare Trust Company of Canada has been duly appointed as the registrar and transfer agent for the Common Shares.

Additional Covenants of the Corporation

The Corporation covenants to the Underwriters that:

(a) the Corporation will advise the Underwriters, promptly after receiving notice thereof, of the time when the Prospectus Supplement and any Amendment have been filed and a Passport System receipt therefor, as applicable, has been obtained and will provide evidence reasonably satisfactory to the Underwriters of each such filing and a copy of any such Passport System receipt;

(b) the Corporation will advise the Underwriters, promptly after receiving notice or obtaining knowledge thereof, of: (i) the issuance by any securities regulatory authority of any order suspending or preventing the use of the Prospectus or any Amendment; (ii) the suspension of the qualification of the Offered Shares in any of the Qualifying Jurisdictions; (iii) the institution, threatening or contemplation of any proceeding for any purposes listed in (i) or (ii) above; or (iv) any requests made by any securities regulatory authority for amending or supplementing the Prospectus or for additional information, and will use its commercially reasonable efforts to prevent the issuance of any order or suspension referred to in (i) and (ii) above and, if any such order is issued, to obtain the withdrawal thereof as quickly as possible;

(c) from and including the date of this Agreement through to and including the Closing Time, will do all such acts and things necessary to ensure that the representations and

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warranties of the Corporation contained in this Agreement or any certificates or documents delivered by the Corporation pursuant to this Agreement remain materially true and correct and not do any such act or thing that would render any representation or warrant of the Corporation contained in this Agreement or any certificates or documents delivered by it pursuant to this Agreement materially untrue or incorrect;

(d) the Corporation will file or cause to be filed with the TSX all necessary documents and will take or cause to be taken all necessary steps to ensure that the Offered Shares have been approved for listing and posted for trading on the TSX prior to the Closing Date, subject only to satisfaction by the Corporation of the customary post-closing conditions imposed by the TSX in similar circumstances;

(e) during the Distribution of the Offered Shares, the Corporation will consult with the Underwriters and promptly provide to the Joint Bookrunners, on behalf of the Underwriters, drafts of any press releases of the Corporation for review by the Joint Bookrunners, on behalf of the Underwriters, and the Underwriters' counsel prior to issuance, and shall obtain the prior approval of the Joint Bookrunners, on behalf of the Underwriters, as to the content and form of any press release prior to issuance, provided that any such approval will not be unreasonably withheld or delayed. Furthermore, to deal with the possibility that the Offered Shares may be sold to purchasers resident in the United States, an appropriate legend concerning such sales shall be included on the top of the Canadian press release, as follows: "Not for distribution to U.S. news wire services or dissemination in the U.S";

(f) the Corporation shall, prior to the completion of the Distribution of the Offered Shares in the Qualifying Jurisdictions, take or use its reasonable commercial efforts to cause to be taken all steps and proceedings that may be required under Securities Laws to qualify the Offered Shares for sale to the public in the Qualifying Jurisdictions through registrants registered under applicable laws who have complied with the relevant provisions of Securities Laws;

(g) prior to the completion of the Distribution of the Offered Shares in the Qualifying Jurisdictions, the Prospectus and any Amendment will comply with the requirements of Securities Laws, will provide full, true and plain disclosure of all material facts relating to the Corporation, its Subsidiaries and to the Offered Shares to the extent required by Securities Laws and will not contain any misrepresentation (provided that the foregoing covenant of the Corporation shall not apply to facts or information relating solely to and provided by the Underwriters or which are modified by or superseded by facts or information contained in the Prospectus or any Amendment);

(h) will use its commercially reasonable efforts to maintain its status as a "reporting issuer" (or the equivalent thereof) not in default of the requirements of the Securities Laws in the Qualifying Jurisdictions until the date that is one year following the Closing Date, provided that this covenant shall not prevent the Corporation from completing any transaction (an "Excluded Transaction") which would result in the Corporation ceasing to be a "reporting issuer" so long as the holders of the Common Shares receive securities of an entity which is listed on a recognized stock exchange in North America, or cash, or the holders of the Common Shares have approved the transaction in accordance with the requirements of applicable corporate laws and securities laws and stock exchange rules and policies;

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(i) will use its commercially reasonable efforts to remain listed for trading on the Toronto Stock Exchange until the date that is one year following the Closing Date, provided that this covenant shall not prevent the Corporation from completing any Excluded Transaction; and

(j) the Corporation will use the net proceeds from the offering of the Offered Shares as described in the Prospectus Supplement, subject to the qualifications set forth therein.

Closing

The purchase and sale of the Offered Shares shall be completed at the Closing Time via electronic exchange of applicable closing deliverables, or at such other place as the Underwriters and the Corporation may agree. At or prior to the Closing Time, the Corporation shall duly and validly deliver to the Underwriters the Offered Shares (whether in definitive form or electronic form) registered in such name or names as the Joint Bookrunners, on behalf of the Underwriters, may notify the Corporation in writing not less than 48 hours prior to Closing Time or as otherwise directed by the Joint Bookrunners, on behalf of the Underwriters, in writing, against payment by the Underwriters to the Corporation, at the direction of the Corporation, in lawful money of Canada by cheque or wire transfer an amount equal to the aggregate purchase price for the Offered Shares being issued and sold hereunder less the Commission. Payment for any Additional Shares purchased pursuant to the Over-Allotment Option shall be made to the Corporation in immediately available funds in Calgary against delivery of such Additional Shares for the respective accounts of the Underwriters or as the Underwriters may otherwise direct at the Over-Allotment Option Closing Time on the Over-Allotment Option Closing Date. In the case of interests in Offered Shares held through CDS or its nominee, if requested by the Joint Bookrunners, on behalf of the Underwriters, the Corporation will deposit such Offered Shares electronically with CDS through the non-certificated inventory system of CDS. It is acknowledged and agreed by the Corporation that all Offered Shares issued and sold pursuant to Rule 144A under the U.S. Securities Act will not contain any restrictive legends and may be deposited electronically with CDS through the non-certificated inventory system of CDS, subject to the execution and delivery of a U.S. purchaser's letter, in the form attached as Exhibit A to the U.S. Placement Memorandum, by each Qualified Institutional Buyer that purchases Offered Shares.

Over-Allotment Option

(a) The Joint Bookrunners, on behalf of the Underwriters, may exercise the Over-Allotment Option, in whole or in part, at any time and from time to time up to 30 days from and including the Closing Date by delivery of written notice to the Corporation of the number of Additional Shares in respect of which the Over-Allotment Option is being exercised and the date for delivery of the Additional Shares (an "Over-Allotment Option Notice"). The Over-Allotment Option Closing Date shall be determined by the Joint Bookrunners but shall not be earlier than two Business Days or later than seven Business Days after delivery of the Over-Allotment Option Notice. Upon delivery of an Over-Allotment Option Notice, the Corporation shall become obligated to sell the total number of Additional Shares in respect of which the Underwriters are exercising the Over-Allotment Option and, subject to the terms and conditions herein set forth, each Underwriter, severally and not jointly, shall become obligated to purchase from the Corporation the percentage set forth in Schedule A of the total number of Additional Shares in respect of which the Underwriters are then exercising the Over-Allotment Option (adjusted if necessary to avoid fractional shares).

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(b) If the Underwriters exercise the Over-Allotment Option in accordance with Section 9(a), the closing of the purchase and sale of the Additional Shares will be completed remotely via electronic transmission of documentation (such as by use of PDF) or at such place determined in writing by the Corporation and the Underwriters. At the Over-Allotment Option Closing Time:

(i) the Corporation will deliver to the Underwriters the items listed in Sections 10(i) and 10(l), if applicable, in each case as if references therein to the "Closing Date" were references to the "Over-Allotment Option Closing Date" and references to the "Closing Time" were references to the "Over-Allotment Option Closing Time", and such other certificates, opinions, agreements, materials or documents, in form and substance satisfactory to the Underwriters and their counsel, as the Underwriters or their counsel may reasonably request;

(ii) the Joint Bookrunners, on behalf of the Underwriters, will cause to be sent to the Corporation by wire transfer (or other means of providing immediately available funds) an amount representing the aggregate purchase price for the Additional Shares, net of the applicable portion of the Underwriting Fee to be paid to the Underwriters at the Over-Allotment Option Closing Time in respect of the Additional Shares; and

(iii) the Corporation will deliver to the Joint Bookrunners, on behalf of the Underwriters, an instant deposit in electronic form representing the Additional Shares registered in the name of CDS or its nominee (or as directed in writing by the Joint Bookrunners not less than one full Business Day before the Over-Allotment Option Closing Time).

Closing Conditions

The Underwriters' obligations under this Agreement are conditional upon and subject to the following conditions being fulfilled at or prior to the Closing Time, which conditions may be waived in writing in whole or in part by the Underwriters:

(a) all actions required to be taken by or on behalf of the Corporation, including without limitation the passing of all requisite resolutions of directors of the Corporation to approve the Prospectus, to obtain the approval of the TSX to the Distribution, to validly offer, sell and distribute the Offered Shares, and to pay the Underwriting Fee shall have been taken;

(b) the Corporation shall have made all necessary filings with and obtained all necessary approvals, consents and acceptances of the Canadian Securities Regulators and applicable third parties for the Prospectus and to permit the Corporation to complete its obligations hereunder;

(c) no order ceasing or suspending trading in any securities of the Corporation, or prohibiting the trade or Distribution of any of the securities of the Corporation will have been issued and no proceedings for such purpose, to the best of the knowledge of the Corporation, will be pending or threatened;

(d) no Underwriter will have exercised any rights of termination set forth in this Agreement;

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(e) the Underwriters shall have received certificates of good standing or similar certificates with respect to the jurisdictions in which the Corporation is incorporated, dated within one Business Day of the Closing Date;

(f) the Underwriters shall have received at the Closing Time one or more definitive certificates (or if requested by CIBC on behalf of the Underwriters, evidence of uncertificated positions) representing in aggregate the Offered Shares registered in the name of "CDS & Co.", or in such other name or names as CIBC shall notify the Corporation in writing not less than 24 hours prior to the Closing Time, against delivery of the aggregate purchase price, net of the Underwriting Fee by bank draft or wire transfer payable to or to the order of the Corporation;

(g) the Underwriters shall have received at the Closing Time a certificate dated as of the Closing Date and signed on behalf of the Corporation by the Executive Vice President and Chief Financial Officer and Vice President, Treasury of the Corporation or such other persons as may be agreed upon by the Underwriters, acting reasonably, certifying (in their capacity as officers of the Corporation, as the case may be, and not in their personal capacity) that to the knowledge, information and belief of such persons, after having made or caused to be made reasonable inquiries and having carefully examined the Prospectus and any Amendment and except as may be disclosed in the Prospectus or any Amendment:

(i) no order ceasing or suspending trading in any securities of the Corporation (including the Offered Shares) has been issued and, to the knowledge of such persons, no proceedings for such purposes are pending or threatened;

(ii) since the date of the Prospectus Supplement, there has been no material change and no material fact has arisen, come into existence or been discovered as contemplated by Section 5 (other than a change or fact related to the Underwriters);

(iii) the representations and warranties of the Corporation herein are true and correct in all material respects at the Closing Time as if made as at such time;

(iv) the Corporation has complied in all material respects with all covenants and satisfied all terms and conditions hereof to be complied with and satisfied by it except to the extent that the same have been waived by the Underwriters in writing pursuant hereto; and

(v) as to such other matters as the Underwriters may reasonably request;

(h) the Underwriters shall have receive a certificate dated the Closing Date signed by the Executive Vice President and Chief Financial Officer and Vice President, Treasury of the Corporation, in form and content acceptable to the Underwriters and their legal counsel, acting reasonably, with respect to:

(i) the articles and by-laws of the Corporation;

(ii) resolutions of the Corporation's board of directors relevant to, among other things, the issue and sale of the Offered Shares to be issued and sold by the

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Corporation and the authorization of this Agreements and the other agreements and transactions contemplated herein; and

(iii) the incumbency and signatures of the signing officers of the Corporation;

(i) the Underwriters shall have received favourable legal opinions dated the Closing Date on behalf of the Underwriters from Blake, Cassels & Graydon LLP and on behalf of the Corporation by Torys LLP, with respect to all such matters of Canadian and provincial law in Alberta, Quebec and Ontario and from local counsel acceptable to Torys LLP and Blake, Cassels & Graydon LLP as to matters governed by laws of jurisdictions in Canada other than the provinces of Alberta, Quebec and Ontario as the Underwriters may reasonably request, including opinion paragraphs substantially as set forth in Schedule C hereto;

(j) if any Offered Shares are being sold in the United States pursuant to Schedule B attached hereto, the Underwriters shall have received an opinion dated the Closing Date, and subject to customary qualifications, of Torys LLP, United States counsel to the Corporation, addressed to the Underwriters, in form and content acceptable to the Underwriters and their legal counsel, acting reasonably, to the effect that no registration of the offer and sale of the Offered Shares in the United States by the Underwriters pursuant to and in accordance with the terms of this Agreement is required under the U.S. Securities Act, provided that such offers and sales of Offered Shares in the United States are made in accordance with Schedule B attached hereto, it being understood that such counsel shall express no opinion as to any subsequent reoffer or resale of the Offered Shares;

(k) the Corporation shall not be or be deemed to be a reporting issuer or the equivalent thereof not in good standing and shall not be in default of any Securities Laws in the Qualifying Jurisdictions at the Closing Time if in the opinion of the Underwriters, acting reasonably, such failure to be in good standing or such default could have a material adverse effect on the Corporation or the offering of Offered Shares;

(l) the Underwriters shall have received at the Closing Time a comfort letter from EY, the auditors of the Corporation, dated the date of delivery and acceptable in form and substance to the Underwriters bringing the information contained in the comfort letter referred to in Section 3(b)(vi) forward to the Closing Time, provided that such comfort letter shall be based on a review by the auditors having a cut-off date not more than two Business Days prior to the Closing Time;

(m) the Corporation shall have furnished to the Underwriters evidence that Offered Shares have been conditionally approved for listing and trading on the TSX and that the Offered Shares will be posted for trading on the TSX on the Closing Date;

(n) at the time of delivery to the Underwriters of the French language version of the Prospectus Supplement:

(i) opinions of Lavery de Billy, L.L.P. and McCarthy Tétrault LLP, addressed to the Corporation, the Underwriters and their respective counsel and dated the date of the Prospectus Supplement, to the effect that the French language version of the Prospectus Supplement (except for the Financial Statements and other financial information included or incorporated by reference therein which are the subject

25 -

of the opinion of the Corporation's auditors referred to below, as to which no opinion need be expressed by McCarthy Tétrault LLP) is in all material respects a complete and proper translation of the English language version thereof; and

(ii) an opinion of the Corporation's auditors, addressed to the Corporation, the Underwriters and their respective counsel and dated the date of the Prospectus Supplement, to the effect that the French language version of the Financial Statements and other financial information set forth or incorporated by reference in the Prospectus Supplement is in all material respects a complete and proper translation of the English language version thereof;

(o) the Underwriters and their counsel shall have been provided with information and documentation, reasonably requested relating to their due diligence inquiries and investigations and shall not have identified any material adverse changes or misrepresentations or any items materially adversely affecting the Corporation's affairs which exist as of the date hereof but which have not been disseminated to the public in accordance with applicable Securities Laws;

(p) the Underwriters shall have received a certificate from the Transfer Agent as to the number of Common Shares issued and outstanding as at the close of business on the Business Day prior to the Closing Date; and

(q) prior to the Closing Time, the Corporation shall have furnished to the Underwriters such further information, certificates and documents as the Underwriters may reasonably request.

Indemnity

(a) Indemnity. The Corporation (the "Indemnifying Party") covenants and agrees that it shall (subject to Sections 11(e) and 12) protect, indemnify and hold harmless the Underwriters and their affiliates and their respective shareholders, directors, officers, partners, employees and agents (the "Indemnified Parties") from and against all losses (other than loss of profit and consequential damages in connection with the Distribution of the Offered Shares), claims, costs, damages and liabilities caused by or arising directly or indirectly by reason of:

(i) any breach of or default under any representation, warranty, covenant or agreement made by the Corporation in this Agreement or any other document to be delivered pursuant hereto;

(ii) any information or statement (except any information or statement furnished in writing by and relating solely to the Underwriters or any of them) contained in the Prospectus, or any Amendment or any document incorporated by reference in such Prospectus or Amendment being or being alleged to be a misrepresentation or untrue or any omission or alleged omission to state therein any fact or information (except facts or information relating to the Underwriters or any of them) required to be stated therein or necessary to make any of the statements therein not misleading in light of the circumstances in which they were made;

(iii) the non-compliance or alleged non-compliance by the Corporation with Securities Laws; or

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(iv) any order made or any inquiry, investigation or proceeding commenced or threatened by any securities regulatory authority or by any other competent authority, based upon any untrue statement, omission or misrepresentation or alleged untrue statement, omission or misrepresentation (except a statement, omission or misrepresentation relating solely to the Underwriters or any of them) in the Prospectus or any Amendment or any document incorporated by reference in such Prospectus or Amendment (except any document or material delivered or filed by the Underwriters or any of them) preventing or restricting the trading in, the sale or Distribution of the Offered Shares in any of the Qualifying Jurisdictions.

(b) Notification of Claims. If any claim contemplated by this Section 11 shall be asserted against any of the Indemnified Parties, or if any potential claim contemplated by this Section 11 shall come to the knowledge of any of the Indemnified Parties, the Indemnified Party concerned shall give notice to the Indemnifying Party as soon as possible of the nature of such claim (provided that any failure to so notify in respect of any potential claim shall not affect the Indemnifying Party's liability and provided further that any failure to so notify in respect of any actual claim shall affect the Indemnifying Party's liability under this Section 11 only to the extent that they are materially prejudiced by such failure).

(c) Retaining Counsel. The Indemnifying Party shall, subject as hereinafter provided, be entitled (but not required) to assume conduct of any negotiations, defence or settlement on behalf of the Indemnified Party of any such claim or any suit brought to enforce such claim; provided that the conduct of any negotiations, defence or settlement shall be through legal counsel acceptable to the Indemnified Party, acting reasonably, and no admission of liability shall be made by the Indemnifying Party without the prior written consent of all parties hereto, such consent not to be unreasonably withheld. An Indemnified Party shall have the right to retain separate counsel in any such suit and participate in the defence thereof but the fees and expenses of such counsel shall be at the expense of the Indemnified Party unless:

(i) the Indemnifying Party fails to assume the defence of such suit on behalf of the Indemnified Party within seven Business Days of receiving notice of such suit;

(ii) the employment of such counsel has been authorized by the Indemnifying Party; or

(iii) the named parties to any such suit (including any added or third parties) include both the Indemnified Party and the Indemnifying Party and the Indemnified Party shall have been advised by counsel that the representation of both parties by the same counsel would be inappropriate due to the actual differing interests between them or there may be one or more legal defences available to the Indemnified Party which are different from or in addition to those available to the Indemnifying Party;

(in the case of each of (c)(i), (ii) and (iii) the Indemnifying Party shall not have the right to assume the defence of such suit on behalf of the Indemnified Party but shall be liable to pay the reasonable fees and expenses of one firm of separate counsel acceptable to the Indemnifying Party, acting reasonably, for all Indemnified Parties and, in addition, one

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firm of local counsel acceptable to the Indemnifying Party, acting reasonably, in each applicable jurisdiction).

(d) Right of Indemnity in Favour of Others. It is the intention of the Indemnifying Party to constitute each Underwriter as the trustee for the respective Underwriters' affiliates, directors, shareholders, officers, employees and agents of the covenants of the Indemnifying Party under this Section 11 with respect to such Underwriter's directors, shareholders, officers, employees and agents and each Underwriter agrees to accept such trust and hold and enforce such covenants on behalf of such persons.

(e) Indemnity not Available. Notwithstanding the provisions of Section 11, the foregoing rights of indemnity shall not enure to an Indemnified Party if the Indemnifying Party has complied with the provisions of Sections 3(e), 4 and 5 and the claim for indemnification relates to a person asserting a claim in respect of an alleged untrue statement in or alleged omission from the Prospectus, or any Amendment thereto, and such person was not provided with a copy of the document which corrects such alleged untrue statement or alleged omission and which is required, under applicable law, to be sent or delivered to such person by such Indemnified Party.

Contribution

In order to provide for just and equitable contribution in circumstances in which the indemnity provided in Section 11 would otherwise be available in accordance with its terms but is, for any reason not attributable to any one or more of the Indemnified Parties, held to be unavailable to or unenforceable by an Indemnified Party or is insufficient to hold the Indemnified Party harmless, the Indemnifying Party shall contribute to the aggregate of all claims, expenses, costs and liabilities and all losses (other than loss of profits and consequential damages) of the nature contemplated in Section 11 (including legal fees and disbursements) and suffered or incurred by the Indemnified Parties in such proportions so that the Indemnified Parties are responsible for that portion thereof as is represented by the percentage that the total Underwriting Fee payable by the Corporation bears to the total gross proceeds to the Corporation of the sale of the Offered Shares (including the Underwriting Fee), both as determined pursuant to the provisions thereof, and the Indemnifying Party shall be responsible for the balance whether or not they have been sued or sued separately; provided that the Indemnified Parties shall not in any event be liable to contribute, in the aggregate, any amount in excess of such total Underwriting Fee or any portion thereof actually received.

The rights to contribution provided in this Section 12 shall be in addition to and not in derogation of any other right to contribution which the Indemnified Parties may have by statute or otherwise at law. If an Indemnified Party has reason to believe that a claim for contribution may arise, the Indemnified Party shall give the Indemnifying Party notice thereof in writing, but failure to so notify shall not relieve the Indemnifying Party of any obligation which they may have to the Indemnified Party under this Section 12, except to the extent that they are materially prejudiced by such failure, and the right of the Indemnifying Party to assume the defence of such Indemnified Party shall apply as set out in Section 11, with necessary changes in detail.

The Indemnifying Party further agrees not to claim contribution from the Indemnified Parties in the event of any action brought against the Indemnifying Party as a result of any information, statement or omission referred to in Section 11(a)(ii) (except any information or statement or omission relating to the Underwriters or any of them).

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13. Expenses of the Distribution

Whether or not the transactions herein contemplated are completed, all expenses of or incidental to the issue and offering of the Offered Shares shall be borne by the Corporation, including, without limitation, expenses payable in connection with the qualification of the Offered Shares for Distribution in the Qualifying Jurisdictions; the preparation, printing, issuance and delivery of certificates for the Offered Shares, including any stamp or transfer taxes in connection with the original issuance and sale of the Offered Shares; the travel, transportation and other expenses in connection with presentations to prospective purchasers of the Offered Shares; all other costs and expenses of the Corporation and its representatives incidental to the performance by the Corporation of its obligations hereunder; the fees and expenses of counsel and auditors for the Corporation; listing fees; and all costs incurred in connection with the preparation, translation, printing, filing and delivery of the Base Shelf Prospectus, the Prospectus Supplement, any marketing materials and any Amendment or supplement to any of them, excepting Underwriters' out-of-pocket expenses and the fees and expenses of counsel for the Underwriters. The Underwriters' reasonable out-of-pocket expenses and fees and expenses of counsel for the Underwriters shall be paid by the Underwriters except that the Underwriters will be reimbursed by the Corporation for all of the reasonable fees and expenses incurred by the Underwriters (including the reasonable fees and expenses of their counsel) if the sale of the Offered Shares as contemplated herein is not completed other than by reason of default by any of the Underwriters.

14. Recognition of the U.S. Special Resolution Regimes

(a) In the event that any Underwriter that is a Covered Entity becomes subject to a proceeding under a U.S. Special Resolution Regime, the transfer from such Underwriter of this Agreement, and any interest and obligation in or under this Agreement, will be effective to the same extent as the transfer would be effective under the U.S. Special Resolution Regime if this Agreement, and any such interest and obligation, were governed by the United States or a state of the United States.

(b) In the event that any Underwriter that is a Covered Entity or a BHC Act Affiliate of such Underwriter becomes subject to a proceeding under a U.S. Special Resolution Regime, Default Rights under this Agreement that may be exercised against such Underwriter are permitted to be exercised to no greater extent that such Default Rights could be exercised under the U.S. Special Resolution Regime if this Agreement were governed by the laws of the United States of America or a state of the United States of America.

(i) "BHC Act Affiliate" has the meaning assigned to the term "affiliate" in, and shall be interpreted in accordance with, 12 U.S.C. § 1841(k).

(ii) "Covered Entity" means any of the following:

A. a "covered entity" as that term is defined in, and interpreted in accordance with, 12 C.F.R. § 252.82(b);

B. a "covered bank" as that term is defined in, and interpreted in accordance with, 12 C.F.R. § 47.3(b); or

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C. a "covered FSI" as that term is defined in, and interpreted in accordance with, 12 C.F.R. § 382.2(b).

(iii) "Default Right" has the meaning assigned to that term in, and shall be interpreted in accordance with, 12 C.F.R. §§ 252.81, 47.2 or 382.1, as applicable.

(iv) "U.S. Special Resolution Regime" means each of (i) the Federal Deposit Insurance Act and the regulations promulgated thereunder and (ii) Title II of the Dodd-Frank Wall Street Reform and Consumer Protection Act and the regulations promulgated thereunder.

Termination

In addition to any other remedies which may be available to the Underwriters, any Underwriter shall be entitled, at the Underwriter's option, to terminate and cancel the Underwriter's obligations under this Agreement if:

(a) any inquiry, action, suit, investigation or other proceeding whether formal or informal is announced, threatened or commenced or any order is issued under or pursuant to any statute, or otherwise (except for any inquiry, investigation or other proceeding, or any order, based upon the activities or alleged activities of the Underwriters or the Selling Firms); or any law or regulation is promulgated, changed or announced which, in the opinion of the Underwriter, acting reasonably, operates to prevent or restrict the trading in the Common Shares or the completion of the offering of Common Shares or would be expected to have a material adverse effect on the market price or value of the Common Shares, by giving the Corporation written notice to that effect at any time prior to the Closing Time;

(b) any order to cease or suspend trading in any securities of the Corporation, or prohibiting or restricting the Distribution of the Common Shares is made, or any proceedings are announced, commenced or threatened for the making of any such order, by any securities commission or similar regulatory or judicial authority or the TSX (other than as a result of any act or omission of the Underwriter contrary to the terms of this Agreement), and the same has not been rescinded, revoked or withdrawn;

(c) prior to the Closing Time, there shall occur any change or any material fact shall arise, come into existence or be discovered as is contemplated in Section 5 (other than a change or fact related to the Underwriter), which in the Underwriter's opinion could be reasonably expected to have a material adverse effect on the market price or value of the Common Shares, by giving the Corporation written notice to that effect prior to Closing Time;

(d) prior to the Closing Time, there should develop, occur or come into effect any occurrence of national or international consequence or any action, government law or regulation or inquiry which in the Underwriter's reasonable opinion seriously adversely affects, or may seriously adversely affect, the financial markets or the business of the Corporation in each case taken as a whole, by giving the Corporation written notice to that effect prior to the Closing Time;

(e) the Underwriters shall become aware, through their due diligence investigations or otherwise, of any material information with respect to the Corporation or any of its

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Subsidiaries which had not been publicly disclosed or disclosed in writing to the Underwriters at or prior to the date hereof and which in the sole opinion of the Underwriters or any one of them, acting reasonably, could be expected to have a significant adverse effect on the market price or value of the Common Shares, or which adversely impacts the Distribution or the marketability of the Common Shares; or

(f) the Corporation shall be in breach or default under or non-compliance with any representation, warranty, covenant, term or condition of this Agreement, in any material respect.

If any Underwriter terminates its obligations hereunder pursuant to this Section 15, the liability of the Corporation hereunder to the Underwriter, if any, and the liability of the Underwriter hereunder to the Corporation, if any, shall be limited to the respective obligations of such parties under Sections 11, 12 and 13.

Underwriting Percentages

(a) The Underwriters' obligation to purchase the Offered Shares at the Closing Time shall be several and not joint, and the Underwriters' respective obligations in this respect shall be as to the percentages set forth in Schedule A of the aggregate amount of Offered Shares to be purchased at the Closing Time.

(b) If one or more of the Underwriters shall fail or refuse to purchase its or their applicable percentages set forth in Schedule A of the aggregate amount of the Offered Shares at the Closing Time and the number of such Offered Shares which such defaulting Underwriter or Underwriters agreed but failed or refused to purchase is not more than 10% of the aggregate number of Offered Shares to be purchased at the Closing Time the non-defaulting Underwriters shall be obligated severally, in the proportions that the respective percentage set forth in Schedule A opposite their name bears to the aggregate of the percentages set forth opposite the names of all such non-defaulting Underwriters, to purchase the Offered Shares which such defaulting Underwriter or Underwriters agreed but failed or refused to purchase at such time.

(c) If any one or more of the Underwriters shall not purchase its applicable percentage of the Offered Shares at the Closing Time and the number of such Offered Shares which such defaulting Underwriter or Underwriters agreed but failed or refused to purchase is more than 10% of the aggregate number of Offered Shares to be purchased at such time, then the other Underwriters shall have the right, but shall not be obligated, to purchase all of the Offered Shares which would otherwise have been purchased by such defaulting Underwriters; the non-defaulting Underwriters exercising such right shall purchase such Offered Shares pro rata to their respective percentages as set forth in Section 16(a) or in such other proportions as they may otherwise agree. If such right is exercised, the non-defaulting Underwriters shall have the right to postpone the Closing Date for such period, not exceeding five Business Days in order that the required changes, if any, including an Amendment to the Prospectus Supplement or in any other documents or arrangements may be effected. If such right is not exercised, each of the other Underwriters not in default shall be relieved of all obligations to the Corporation under this Agreement upon submission to the Corporation of reasonable evidence of its ability and willingness to fulfil its obligations hereunder at the Closing Time. Nothing in this Section 16 shall oblige the Corporation to sell to any or all of the Underwriters

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less than all of the aggregate amount of the Offered Shares or shall relieve any of the Underwriters in default hereunder from liability to the Corporation.

(d) Nothing in this Agreement shall oblige any United States registered broker-dealer affiliates of any of the Underwriters to purchase the Offered Shares. Any such U.S. affiliate who makes any offers or sales of the Offered Shares in the United States will do so solely as an agent for an Underwriter.

(e) After a reasonable effort has been made to sell all of the Offered Shares at the Offering Price, the Underwriters may subsequently reduce the issue price to investors from time to time, provided that any such reduction in the Offering Price shall not result in the Corporation realizing net proceeds (after deducting the Commission and the Underwriters' expenses) from the issuance of the Offered Shares in an amount which is less than the amount the Corporation would have realized without any reduction in the issue price. The Underwriters will inform the Corporation if the Offering Price is decreased.

(f) The Corporation acknowledges that the Underwriters and certain of their affiliates: (i) act as a trader of, and dealer in, securities both as principal and on behalf of its clients and, as such, may have had, and may in the future have, long or short positions in the securities of the Corporation or related entities and, from time to time, may have executed or may execute transactions on behalf of such persons; (ii) may provide research or investment advice to clients on investment matters, including the Corporation; (iii) may participate in securities transactions on a proprietary basis, including transactions in the Distribution or other securities of the Corporation or related entities and, (iv) nothing herein shall restrict their ability to conduct business in the ordinary course and in compliance with applicable laws.

Black-out Period

Subject to and conditional upon closing of the Distribution, the Corporation hereby agrees that without the prior consent of the Joint Bookrunners on behalf of the Underwriters, which consent shall not be unreasonably withheld, it will not, during the period ending 90 days after the Closing Date (i) issue, agree or publicly disclose the intention to issue, create, allot, authorize, offer, secure, pledge, sell, contract to sell, sell any option or contract to purchase, purchase any option or contract to sell, grant any option, right or warrant to purchase, or otherwise lend, transfer or dispose of, directly or indirectly any Common Shares or any securities convertible into or exchangeable for Common Shares, other than pursuant to: (a) the grant, exercise or settlement of stock options or other similar securities issuances pursuant to the securities incentive plans of the Corporation or other share compensation arrangements entered into by the Corporation; (b) the exercise of outstanding convertible or exchangeable securities; (c) obligations or rights of the Corporation in respect of existing agreements; (d) the issuance of securities by the Corporation in connection with bona fide arm's length acquisitions; and (e) any internal reorganizations by the Corporation, or (ii) enter into any swap or other arrangement that transfers to another, in whole or in part, any of the economic consequences of ownership of equity securities of the Corporation.

Termination/Waiver

All material terms and conditions of this offer shall be construed as conditions, and any breach or failure by the Corporation to comply with any material terms or conditions shall entitle any Underwriter, without limitation of any other remedies of the Underwriters, to terminate such

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Underwriter's obligations to purchase the Offered Shares by giving written notice to that effect to the Corporation prior to the Closing Time. It is understood that each Underwriter may waive in whole or in part, or extend the time for compliance with, any of such terms and conditions without prejudice to such Underwriter's rights in respect of any other of such terms and conditions or any other or subsequent breach or non-compliance, provided that to be binding on an Underwriter any such waiver or extension must be in writing and signed by the Underwriter.

Survival

The representations, warranties, covenants, obligations and agreements of the Corporation contained herein or delivered pursuant hereto shall survive the purchase by the Underwriters of the Offered Shares and shall continue in full force and effect for a period of three years from the Closing Date notwithstanding any subsequent disposition by the Underwriters of the Offered Shares, but where expressly limited to a particular date shall continue to speak only as of such date, and the Underwriters shall be entitled to rely on the representations and warranties of the Corporation contained herein or delivered pursuant hereto notwithstanding any investigation which the Underwriters may undertake or which may be undertaken on the Underwriters' behalf.

Notices

Any notice or other communication to be given hereunder shall be addressed to:

(a) in the case of notice to the Corporation:

AltaGas Ltd.
1300, 707 – 5th Street S.W.
Calgary, Alberta T2P 1V8

Attention: James Harbilas
Executive Vice President and Chief Financial Officer
Email: [email protected]

(b) and, in the case of notice to the Underwriters, to the attention of the Joint Bookrunners:

CIBC World Markets Inc.
855 – 2nd Street SW, 9th Floor
Calgary, Alberta T2P 4J7

Attention: Douglas Pearce
Managing Director & Co-Head, Energy, Infrastructure & Transition
Email: [email protected]

TD Securities Inc.
421 – 7 Avenue Southwest
Calgary, Alberta T2P 4K9

Attention: Scott Barron
Managing Director & Head of Calgary Investment Banking
Email: [email protected]

RBC Capital Markets
3900, 888 – 3rd Street SW
Calgary, AB T2P 5C5

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Attention: Curtis Dunford
Managing Director
Email: [email protected]

Scotia Capital Inc.
Brookfield Place, Suite 1700
225 - 6 Avenue S.W.
Calgary, Alberta T2P 1N2

Attention: Dan Beck
Managing Director
Email: [email protected]

Each notice shall be personally delivered to the addressee or sent by e-mail to the addressee. A notice which is personally delivered or delivered by e-mail shall, if delivered prior to 5:00 p.m. (Calgary time) on a Business Day, be deemed to be given and received on that day and, in any other case, be deemed to be given and received on the first Business Day following the day on which it is delivered. Any party may change its address for notice by notice to the other parties hereto given in the manner herein provided.

Time

Time shall be of the essence in this Agreement and, following any waiver or indulgence by any party, time shall again be of the essence of this Agreement.

Governing Law

This Agreement shall be governed by and interpreted in accordance with the laws of the Province of Alberta and the federal laws of Canada applicable in the Province of Alberta and the parties hereto irrevocably attorn to the non-exclusive jurisdiction of the Courts of the Province of Alberta.

Attachment

The parties hereby irrevocably and unconditionally consent to and submit to the courts of Alberta for any actions, suits or proceedings arising out of or relating to this Agreement or the matters contemplated hereby (and agree not to commence any action, suit or proceeding relating thereto except in such courts) and further agree that service of any process, summons, notice or document by single registered mail to the address of the parties set forth in this Agreement shall be effective service of process for any action, suit or proceeding brought against either party in such court. The parties hereby irrevocably and unconditionally waive any objection to the laying of venue of any action, suit or proceeding arising out of this Agreement or the matters contemplated hereby in the courts of Alberta and hereby further irrevocably and unconditionally waive and agree not to plead or claim in any such court that any such action, suit or proceeding so brought has been brought in an inconvenient forum.

Over-Allotment/Stabilization

In connection with the Distribution of the Offered Shares, the Underwriters and the Selling Firms may over-allot or effect transactions which stabilize or maintain the market price of the Offered Shares at levels other than those which might otherwise prevail in the open market, but in each

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case only as permitted by applicable law. Such stabilizing transactions, if any, may be discontinued at any time.

Severability

If any provision hereof is determined to be void or unenforceable in whole or in part, it shall be deemed not to impair or affect the validity of any other provision of this Agreement, and such void or unenforceable provision shall be severable from this Agreement.

Entire Agreement

This Agreement constitutes the entire agreement among the parties hereto relating to the purchase by, and sale of the Offered Shares to, the Underwriters and the process leading thereto and supersedes all prior agreements between any of those parties with respect to their respective rights and obligations in respect of such transaction and the process leading thereto.

Counterparts/Facsimile Signatures

This Agreement may be executed and delivered (including by facsimile transmission or portable document format (PDF)) in one or more counterparts, and by the different parties hereto in separate counterparts, each of which when executed shall be deemed to be an original, but all of which taken together shall constitute one and the same agreement. The transmission by facsimile transmission or PDF of a copy of the execution page hereof reflecting the execution of this Agreement by any party hereto shall be effective to evidence that party's intention to be bound by this Agreement and that party's agreement to the terms, provisions and conditions hereof, all without the necessity of having to produce an original copy of such execution page.

Authority of the Joint Bookrunners

The Joint Bookrunners are hereby authorized by each of the other Underwriters to act on its behalf and the Corporation shall be entitled to and shall act on any notice given in accordance with Section 20 or any agreement entered into or approval given by or on behalf of the Underwriters by the Joint Bookrunners, who represent and warrant that they have irrevocable authority to bind the Underwriters, except in respect of (i) any consent to a settlement pursuant to Section 11 which consent shall be given by the Indemnified Party, (ii) a notice of termination pursuant to Section 14, which notice may be given by any of the Underwriters, (iii) any exercise of the rights of the Underwriters, under Section 14, which shall be exercised by all the non-defaulting Underwriters, (iv) any waiver pursuant to Section 18, which waiver must be signed by all of the Underwriters; or (v) any approval of any Amendment that amends or supplements the Base Shelf Prospectus, the Prospectus Supplement or the U.S. Placement Memorandum, under Section 4, (which approval must be given by each Underwriter).

No Fiduciary Duty

The Corporation hereby acknowledges that (i) the purchase and sale of the Offered Shares pursuant to this Agreement is an arm's-length commercial transaction between the Corporation on the one hand, and the Underwriters and any affiliate through which they may be acting to effect sales, on the other, (ii) such Underwriters are acting as principal and not as an agent or fiduciary of the Corporation and (iii) the Corporation's engagement of such Underwriters in connection with the offering of the Offered Shares and the process leading up to the offering of the Offered Shares is as independent contractors and not in any other capacity. Furthermore, the Corporation

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agrees that it is solely responsible for making its own judgments in connection with the offering of the Offered Shares (irrespective of whether any of such Underwriters has advised or is currently advising the Corporation on related or other matters). The Corporation agrees that it will not claim that such Underwriters owe an agency, fiduciary or similar duty to the Corporation in connection with such transaction or the process leading thereto. The Underwriters hereby expressly disclaim any fiduciary or similar obligations to the Corporation or any of its Subsidiaries, either in connection with the transactions contemplated by this Agreement or any matters leading up to such transactions, and the Corporation hereby confirms its understanding and agreement to that effect. The Corporation waives and releases, to the fullest extent permitted by applicable laws, any claims that it may have against the Underwriters or any Selling Firm arising from any breach or alleged breach of any fiduciary or similar duty to the Corporation or its Subsidiaries in connection with the transactions contemplated by this Agreement or any matters leading up to such transactions.

Stock Exchange

National Bank Financial Inc. or affiliates thereof, may own or control an equity interest in TMX Group Limited ("TMX Group") and may have a nominee director serving on the TMX Group's board of directors. As such, such investment dealer may be considered to have an economic interest in the listing of securities on any exchange owned or operated by TMX Group or in using any services provided by the TMX Group or its affiliates. National Bank Financial Inc. does not require the Corporation to use any services provided by TMX Group or its affiliates as a condition of supplying or continuing to supply underwriting and/or any other services, including any services provided pursuant to the terms thereof.

[Remainder of this page intentionally left blank; signature page follows]

If the foregoing is acceptable to you, please signify such acceptance by executing and returning the enclosed copy of this Agreement to the Joint Bookrunners, on behalf of the Underwriters. Such acceptance will constitute an agreement for the purchase by the Underwriters and sale by the Corporation of the Offered Shares on the terms set out herein.

Yours very truly,

[Signature Page – Underwriting Agreement]

CIBC WORLD MARKETS INC.
By: (Signed) “Douglas Pearce”
T D SECURITIES INC.
By: (Signed) “Scott Barron”

RBC DOMINION SECURITIES INC.
By: (Signed) “Curtis Dunford”
SCOTIA CAPITAL INC.
By: (Signed) “Dan Beck”

BMO NESBITT BURNS INC.
By: (Signed) “Tim Lisevich”
NATIONAL BANK FINANCIAL INC.
By: (Signed) “Tuc Tuncay”

MERRILL LYNCH CANADA INC.
By: (Signed) “Jamie Hancock”
WELLS FARGO SECURITIES CANADA, LTD.
By: (Signed) “Darin Deschamps”

MIZUHO SECURITIES CANADA INC.
By: (Signed) “James Watts”
ATB SECURITIES INC.
By: (Signed) “Robyn Hemminger”

PETERS & CO. LIMITED
By: (Signed) “Cameron Plewes”
J.P. MORGAN SECURITIES CANADA INC.
By: (Signed) “Sam Johnson”

MORGAN STANLEY CANADA LIMITED
By: (Signed) “Shelly Saidova”
TUDOR, PICKERING, HOLT & CO. SECURITIES – CANADA, ULC
By: (Signed) “Derek Wheatley”

The foregoing agreement is hereby accepted and agreed to as of the date first above written.

ALTAGAS LTD.

Per: (Signed) “James Harbilas”
James Harbilas
Executive Vice President and Chief
Financial Officer

[Signature Page – Underwriting Agreement]

SCHEDULE A

TO
UNDERWRITING AGREEMENT

CIBC World Markets Inc. 22.40%
TD Securities Inc. 14.06%
RBC Dominion Securities Inc. 13.02%
Scotia Capital Inc. 10.94%
BMO Nesbitt Burns Inc. 8.33%
National Bank Financial Inc. 6.25%
Merrill Lynch Canada Inc. 5.0%
Wells Fargo Securities Canada, Ltd. 5.0%
Mizuho Securities Canada Inc. 4.0%
ATB Securities Inc. 3.5%
Peters & Co. Limited 2.5%
J.P. Morgan Securities Canada Inc. 2.0%
Morgan Stanley Canada Limited 1.5%
Tudor, Pickering, Holt & Co. Securities - Canada, ULC 1.5%
100.0%

SCHEDULE B
TO
UNDERWRITING AGREEMENT

UNITED STATES OFFERS AND SALES

Definitions

As used in this Schedule and related exhibits, the following terms shall have the meanings indicated:

“Directed Selling Efforts” means “directed selling efforts” as that term is defined in Rule 902(c) of Regulation S, which, without limiting the foregoing, but for greater clarity in this Schedule, includes, subject to the exclusions from the definition of directed selling efforts contained in Regulation S, any activity undertaken for the purpose of, or that could reasonably be expected to have the effect of, conditioning the market in the United States for the Offered Shares and includes the placement of any advertisement in a publication with a general circulation in the United States that refers to the offering of the Offered Shares;

“Foreign Issuer” means a “foreign issuer” as that term is defined in Rule 902(e) of Regulation S;

“General Solicitation” and “General Advertising” mean “general solicitation” and “general advertising”, respectively, as used in Rule 502(c) under the U.S. Securities Act, including advertisements, articles, notices or other communications published in any newspaper, magazine or similar media or broadcast over radio or television or the internet, or any seminar or meeting whose attendees had been invited by general solicitation or general advertising;

“Investment Company Act” means the U.S. Investment Company Act of 1940, as amended, and the rules and regulations promulgated thereunder;

“Qualified Institutional Buyer” means a “qualified institutional buyer” as such term is defined in Rule 144A;

“Regulation S” means Regulation S adopted by the SEC under the U.S. Securities Act;

“SEC” means the United States Securities and Exchange Commission;

“Substantial U.S. Market Interest” means “substantial U.S. market interest” as that term is defined in Rule 902(j) of Regulation S;

“United States” means the United States of America, its territories and possessions, any state of the United States and the District of Columbia;

“U.S. Affiliate” of any Underwriter means the U.S. registered broker-dealer affiliate of such Underwriter;

“U.S. Exchange Act” means the U.S. Securities Exchange Act of 1934, as amended;

“U.S. Securities Act” means the U.S. Securities Act of 1933, as amended;

“U.S. Purchasers” means purchasers of Offered Shares who are in the United States; and

“U.S. Purchaser’s Letter” means the U.S. Purchaser’s Letter, in substantially the same form appended to the U.S. Placement Memorandum as Exhibit A thereto.

All other capitalized terms used but not otherwise defined in this Schedule shall have the meanings given to them in the Underwriting Agreement to which this Schedule is attached and of which this Schedule forms a part.

Representations, Warranties and Covenants of the Corporation

The Corporation represents, warrants and covenants to the Underwriters that:

(a) it is a Foreign Issuer and reasonably believes that there is no Substantial U.S. Market Interest with respect to the Common Shares;

(b) except with respect to offers and sales by or through the Underwriters to Qualified Institutional Buyers in reliance upon the exemption from registration under the U.S. Securities Act provided by Rule 144A in accordance with this Schedule “A”, neither the Corporation nor any of its affiliates, nor any person acting on its or their behalf (other than the Underwriters, their respective U.S. Affiliates, any members of the banking and selling group formed by them (the “Selling Group”) or any person acting on their behalf, in respect of which no representation, warranty, covenant or agreement is made), has made or will make: (i) any offer to sell, or any solicitation of an offer to buy, any Offered Shares in the United States; or (ii) any sale of Offered Shares to any purchaser unless, at the time the buy order was or will have been originated, either (A) such purchaser is outside the United States, or (B) the Corporation, its affiliates, and any person acting on their behalf (other than the Underwriters, their respective U.S. Affiliates, any Selling Group member or any person acting on their behalf, in respect of which no representation, warranty, covenant or agreement is made) reasonably believe that such purchaser is outside the United States;

(c) in connection with offers and sales of the Offered Shares outside the United States, the Corporation, each of its affiliates, and any person acting on its or their behalf (other than the Underwriters and their U.S. Affiliates or any Selling Group member, as to which no representation or warranty is made) have complied and will comply with the requirements for an “offshore transaction” (as that term is defined in Rule 902(h) of Regulation S);

(d) neither the Corporation nor any of its affiliates, nor any person acting on its or their behalf (other than the Underwriters, the U.S. Affiliates or any members of the Selling Group, as to whom the Corporation makes no representation), has engaged or will engage in any Directed Selling Efforts or any form of General Solicitation or General Advertising (or has acted in any manner involving a public offering within the meaning of Section 4(a)(2) of the U.S. Securities Act) with respect to the Offered Shares, or has taken or will take any action that would cause the applicable exemption or exclusion from registration under the U.S. Securities Act afforded by Rule 144A or Rule 903 of Regulation S to be unavailable for offers and sales of the Offered Shares pursuant to this Agreement;

(e) the Offered Shares are not, and as of the Closing will not be, and no securities of the same class as the Offered Shares are: (i) listed on a national securities exchange in the United States registered under Section 6 of the U.S. Exchange Act; (ii) quoted in an “automated inter-dealer quotation system”, as such term is used in the U.S. Exchange Act; or (iii) convertible or exchangeable into, or exercisable for, securities so listed or quoted at an effective conversion or exercise premium (calculated as specified in paragraph (a)(6) and (a)(7) of Rule 144A) of less than ten percent for securities so listed or quoted;

(f) in connection with the initial resale of the Offered Shares to Qualified Institutional Buyers, the Corporation shall make available to such Qualified Institutional Buyers the information required to be provided pursuant to Rule 144A(d)(4) under the U.S. Securities Act;

(g) for so long as the Offered Shares which have been sold in the United States pursuant to this Agreement are “restricted securities” within the meaning of Rule 144(a)(3) under the U.S. Securities Act, and if the Corporation is neither (i) subject to and in compliance with the reporting requirements of Section 13 or 15(d) of the U.S. Exchange Act nor (ii) exempt from such reporting requirements pursuant to Rule 12g3-2(b) thereunder, the Corporation shall provide to any holders of such Offered Shares, or to any prospective purchasers of such Offered Shares designated by such holders, upon request of such holders or prospective purchasers, at or prior to the time of resale, the information required to be provided by Rule 144A(d)(4) under the U.S. Securities Act (so long as such requirement is necessary in order to permit holders of such Offered Shares to effect resales under Rule 144A), it being understood that each U.S. Purchaser has represented and agreed that no resales of the Offered Shares by any of them may be permitted under Rule 144A following completion of the offering of the Offered Shares, as set forth in the U.S. Purchaser’s Letter;

(h) the Corporation is not, and after giving effect to the offering of the Offered Shares and the application of the proceeds as contemplated herein and the U.S. Placement Memorandum will not be, registered as an investment company nor will it be required to register as an investment company within the meaning of the Investment Company Act;

(i) none of the Corporation’s securities are registered or are required to be registered under Section 12 of the U.S. Exchange Act and the Corporation does not, and will not upon the offer and sale of the Offered Shares, have a reporting obligation under Section 13 or Section 15(d) of the U.S. Exchange Act; and

(j) none of the Corporation or any of its predecessors or subsidiaries has had the registration of a class of securities under the U.S. Exchange Act revoked by the SEC pursuant to Section 12(j) of the U.S. Exchange Act or any similar rules or regulations promulgated under the U.S. Securities Act.

Representations, Warranties and Covenants of the Underwriters

Each Underwriter and U.S. Affiliate jointly and not severally (but not jointly with any other Underwriter or its respective U.S. Affiliate) acknowledges, represents, warrants and covenants to the Corporation that:

(k) it has not offered and sold, and will not offer and sell, any Offered Shares except in an “offshore transaction” in accordance with Rule 903 of Regulation S or in the United States to Qualified Institutional Buyers in accordance with Rule 144A and in compliance with U.S. state securities laws, as provided in the paragraphs set forth below. Accordingly, neither the Underwriter, its U.S. Affiliates nor any persons acting on its or their behalf, has made or will make (except as permitted in the paragraphs set forth below): (i) any offer to sell or any solicitation of an offer to buy, any Offered Shares in the United States; or (ii) any sale of Offered Shares to any purchaser unless, at the time the buy order was or will have been originated, either (A) such purchaser was outside the United States, or (B) the Underwriter, its U.S. Affiliates or persons acting on its behalf reasonably believed that such purchaser was outside the United States;

(l) it and its affiliates, including its U.S. Affiliate, have not, either directly or through a person acting on its or their behalf, solicited and will not solicit offers for, and have not offered to sell and will not offer to sell, any of the Offered Shares in the United States by any form of General Solicitation or General Advertising, Directed Selling Efforts or in any manner involving a public offering within the meaning of Section 4(a)(2) of the U.S. Securities Act;

(m) it has not entered and will not enter into any contractual arrangement with respect to the distribution of the Offered Shares, except with its U.S. Affiliate, any Selling Group members or with the prior written consent of the Corporation;

(n) it shall require each selling group member to agree, for the benefit of the Corporation, to comply with, and shall use its commercially reasonable efforts to ensure that each Selling Group member complies with, the provisions of this Schedule B applicable to the Underwriter as if such provisions applied to such Selling Group member;

(o) all offers and sales of Offered Shares in the United States shall be made by the Underwriter through its U.S. Affiliate (which on the dates of such offers and sales was and will be duly registered as a broker-dealer under the U.S. Exchange Act and under all applicable state securities laws and a member of, and in good standing with, the Financial Industry Regulatory Authority, Inc.), in accordance with all applicable broker-dealer laws and in compliance with this Schedule B;

(p) each U.S. Affiliate selling the Offered Shares in the United States is a Qualified Institutional Buyer;

(q) it will solicit (and will cause its U.S. Affiliate to solicit, as applicable) offers for the Offered Shares in the United States only from, and will offer the Offered Shares only in accordance with Rule 144A to persons whom it reasonably believes to be Qualified Institutional Buyers in accordance with Rule 144A, pursuant to transactions that are exempt from registration under or in compliance with applicable U.S. state securities laws;

(r) it will inform (and will cause its U.S. Affiliate to inform, as applicable) all U.S. Purchasers and all persons who were offered Offered Shares in the United States that

the Offered Shares have not been and will not be registered under the U.S. Securities Act and are being offered and sold to such purchasers and offerees without registration in reliance on the exemption from the registration requirements of the U.S. Securities Act provided by Rule 144A and in compliance with U.S. state securities laws;

(s) it shall cause its U.S. Affiliate to deliver a copy of the U.S. Placement Memorandum, together with the Prospectus Supplement and any amendment thereto, as applicable, to each of its offerees in the United States at or prior to the time of purchase of Offered Shares, as applicable, and no other written material other than the U.S. Placement Memorandum shall be used in connection with the offer or sale of the Offered Shares in the United States;

(t) at Closing it, together with its U.S. Affiliate offering or selling Offered Shares in the United States, will provide a certificate, substantially in the form of Exhibit I to this Schedule B, relating to the manner of the offer and sale of the Offered Shares in the United States, or will be deemed to have represented and warranted for the benefit of the Corporation that neither it nor its U.S. Affiliate offered or sold Offered Shares in the United States; and

(u) prior to the Closing Time, it will deliver signed copies of each U.S. Purchaser’s Letter, from each of the U.S. Purchasers.

EXHIBIT I

UNDERWRITERS' CERTIFICATE

In connection with the offer and sale, under Rule 144A, of common shares of AltaGas Ltd. (the "Company") in the United States pursuant to the Underwriting Agreement dated as of November 5, 2025 among the Company and the underwriters party thereto (the "Underwriting Agreement"), the undersigned [name of Underwriter] (the "Underwriter") and [name of U.S. affiliate of Underwriter], in its capacity as placement agent in the United States for the Underwriter (the "U.S. Affiliate"), each hereby certifies that:

(a) all offers to sell, solicitations of offers to buy and sales of the Offered Shares in the United States were made only through the U.S. Affiliate in compliance with all applicable United States state and federal broker-dealer requirements. The U.S. Affiliate is a Qualified Institutional Buyer, a duly registered broker or dealer with the SEC and in each state applicable to the U.S. Affiliate (unless exempt therefrom) and is a member of and in good standing with the Financial Industry Regulatory Authority, Inc. on the date hereof and at the time of such offers and sales by it of Offered Shares;

(b) all offers and sales of the Offered Shares in the United States have been conducted by us in accordance with the terms of Schedule B to the Underwriting Agreement;

(c) immediately prior to our making of any offers of Offered Shares to offerees in the United States, we had reasonable grounds to believe and did believe that each such offeree was a Qualified Institutional Buyer, and, on the date hereof, we have reasonable grounds to believe and continue to believe that each purchaser of Offered Shares in the United States or who was offered Offered Shares in the United States is a Qualified Institutional Buyer;

(d) no form of General Solicitation or General Advertising was used by us in connection with the offer or sale of the Offered Shares in the United States and we did not engage in any Directed Selling Efforts in connection with the offer or sale of the Offered Shares; and

(e) prior to any sale by us of Offered Shares in the United States, we caused each U.S. Purchaser to execute and deliver a U.S. Purchaser's Letter.

Terms used in this certificate have the meanings given to them in the Underwriting Agreement unless otherwise defined herein.

[Signature page follows]

Dated this _ day of __, 2025.

[NAME OF UNDERWRITER]

[INSERT NAME OF U.S. AFFILIATE]

By: _______
Name:
Title:

SCHEDULE C
TO
UNDERWRITING AGREEMENT

Opinion of Corporation Counsel

This is Schedule C to the Underwriting Agreement dated effective November 5, 2025 between CIBC World Markets Inc., TD Securities Inc., RBC Dominion Securities Inc. and Scotia Capital Inc. and each of the other underwriters listed in Schedule A to this Agreement. This Schedule C is deemed to be incorporated by reference into the Underwriting Agreement.

The Corporation:
(a) has been duly amalgamated and validly exists under the Canada Business Corporations Act; and
(b) has the requisite corporate power and capacity to own, lease and operate its properties and assets and conduct its business as currently conducted and to enter into and perform its obligations under the Underwriting Agreement;
The Corporation is authorized to issue: (i) an unlimited number of Common Shares; and (ii) Preferred Shares issuable in series and limited to such number of Preferred Shares issuable in series at any time as have aggregate voting rights either directly or on conversion or exchange that in the aggregate represent less than 50% of the voting rights attaching to the then issued and outstanding Common Shares.
The attributes of the Offered Shares conform in all material respects with the descriptions thereof in the Prospectus.
The Corporation is a reporting issuer in each of the provinces of Canada, and is not included in a list of defaulting reporting issuers maintained pursuant to the Securities Laws of such provinces.
Computershare Trust Company of Canada has been duly appointed as the transfer agent and registrar for the Common Shares.
No order, ruling or determination having the effect of ceasing, suspending or restricting the distribution or trading of the Offered Shares (of which we are aware) has been issued by any Canadian Securities Regulator in any of the provinces of Canada.
The Corporation has the corporate power and capacity to execute and deliver the Underwriting Agreement, and to perform its obligations set out therein, and the Underwriting Agreement, has been duly authorized, executed and delivered by the Corporation and constitutes a legal, valid and binding obligation of the Corporation, enforceable against the Corporation in accordance with its terms.
The Prospectus and any Amendment have been duly executed and delivered by the Corporation.
The entering into and performance by the Corporation of the Underwriting Agreement, including the creation, issuance and sale of the Offered Shares, does not and will not conflict with, result in a breach of or constitute a default under (whether after notice or lapse of time or both):

(a) the articles and by-laws of the Corporation or any resolutions (of which we are aware) of the directors (or any committee thereof) or shareholders thereof; or

(b) any statute or, to our knowledge, any order, rule or regulation of any court or governmental agency or body having jurisdiction over the Corporation;

except, in the case of (b), where such conflict, breach or default or the consequences thereof, alone or in the aggregate, would not have a material adverse effect on the Corporation or the performance by the Corporation of its obligations under the Underwriting Agreement and the Prospectus.

No consent, approval, authorization or order of or filing with any court or public, governmental or regulatory agency or body governed by the laws of Canada or the Province of Alberta is required to be made or obtained by the Corporation for the execution, delivery and performance by the Corporation of the Underwriting Agreement or for the consummation of the transactions contemplated hereby or thereby, except for such as have been made or obtained under Securities Laws of the Province of Alberta.
All necessary corporate action has been taken by the Corporation to authorize the execution of the Base Shelf Prospectus and the filing of the Base Shelf Prospectus, the Prospectus Supplement and the Marketing Documents in each of the provinces of Canada in accordance with applicable Securities Laws.
All necessary documents have been filed and all requisite proceedings have been taken and all approvals, permits, consents and authorizations of the Canadian Securities Regulators required under applicable Securities Laws have been obtained by the Corporation to qualify the distribution of the Offered Shares in each of the provinces of Canada through persons or companies who are duly registered in an appropriate category of dealer registration under applicable Securities Laws who have complied with the relevant provisions of such laws and the terms of such registration.
Subject to the qualifications, assumptions, limitations and understandings set out therein, the statements set forth in the Prospectus Supplement under the heading "Eligibility for Investment", insofar as such statements constitute statements of law, provide an accurate summary of the matters of Canadian federal income tax law addressed therein in all material respects.
All requirements relating to the use of the French language in the Securities Act (Québec) will have been complied with in connection with the offer and sale of the Offered Shares to purchasers in Québec. We express no opinion as to whether the offering, issuance, sale and delivery of the Offered Shares or any contract or document relating thereto are in compliance with the Charter of the French Language.

AI assistant

AltaGas Ltd. Share Issue/Capital Change 2025

47943_rns_2025-11-05_0b0bf699-5cb1-4a5c-b4e2-2404e1b45fc1.pdf

TERMS AND CONDITIONS

1. Qualification of Offered Shares

13. Expenses of the Distribution

14. Recognition of the U.S. Special Resolution Regimes

SCHEDULE A

EXHIBIT I

UNDERWRITERS' CERTIFICATE

AI assistant

AltaGas Ltd. — Share Issue/Capital Change 2025

47943_rns_2025-11-05_0b0bf699-5cb1-4a5c-b4e2-2404e1b45fc1.pdf

TERMS AND CONDITIONS

1. Qualification of Offered Shares

13. Expenses of the Distribution

14. Recognition of the U.S. Special Resolution Regimes

SCHEDULE A

EXHIBIT I

UNDERWRITERS' CERTIFICATE

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