AltaGas Ltd. — Proxy Solicitation & Information Statement 2025

Mar 25, 2025

AltaGas

NOTICE OF ANNUAL AND SPECIAL MEETING AND AVAILABILITY OF MEETING MATERIALS

ANNUAL AND SPECIAL MEETING DATE, TIME AND LOCATION:

Date: Thursday, May 1, 2025
Time: 1:30 p.m. (MDT)
Where: Online at https://meetings.lumiconnect.com/400-841-462-038
Password: altagas2025 (case sensitive)

NOTICE AND ACCESS

You are receiving this notice as a registered shareholder of AltaGas Ltd. ("AltaGas") because AltaGas is using the notice and access model adopted by the Canadian securities regulators ("N&A") for delivery of meeting materials to its shareholders in respect of the upcoming annual and special meeting of shareholders to be held on May 1, 2025, or any adjournment thereof (the "Meeting"). In connection with the use of N&A, on February 17, 2025, Corporations Canada exempted AltaGas from mailing paper copies of the management information circular (the "Circular"), annual financial statements and the related management's discussion and analysis (collectively, the "Meeting Materials") to each shareholder whose proxy is solicited.

N&A, as supplemented by this exemption, allows us to post Meeting Materials online. See "Websites Where Meeting Materials Are Posted" below. The use of this alternative means of delivery is more environmentally friendly and reduces printing and mailing costs. Meeting Materials will not be mailed to shareholders unless a shareholder follows the instructions below under "How to Obtain Paper Copies of the Meeting Materials". Along with this notice, you will have received a form of proxy enabling you to vote on the matters set out below.

Shareholders with questions about notice and access can call 1-866-964-0492.

MATTERS TO BE VOTED ON AT THE MEETING

At the Meeting, shareholders will be asked to consider and vote on the following matters:

1. APPOINTMENT OF AUDITOR: Shareholders will be asked to re-appoint Ernst & Young LLP as AltaGas' auditor for the ensuing year and authorize the directors to set their remuneration. Information respecting this matter can be found under the heading "Appointment of Auditors" in the Circular.
2. ELECTION OF DIRECTORS: Shareholders will be asked to elect ten directors. Information respecting the director nominees may be found under the heading "Director Nominees" in the Circular.
3. AMENDMENTS TO OPTION PLAN: Shareholders will be asked to approve amendments to convert the number of common shares ("Shares") of AltaGas issuable under the Option Plan from a rolling limit of 5% of the issued and outstanding Shares to a fixed number of 14,500,000. Information respecting this matter may be found under the heading "Approval of Amendment to Option Plan" in the Circular.
4. ADVISORY VOTE ON EXECUTIVE COMPENSATION: Shareholders will be asked to vote on the non-binding advisory resolution to accept AltaGas' approach to executive compensation. Information respecting executive compensation may be found under the headings "Compensation Discussion and Analysis" and "Executive Compensation Information" in the Circular.
5. OTHER BUSINESS: Shareholders may be asked to consider other business that may properly be brought before the meeting or any adjournment of the meeting.

For detailed information, please refer to the Circular. The Circular also includes annual disclosure.

WEBSITES WHERE MEETING MATERIALS ARE POSTED

The Meeting Materials can be viewed online at www.sedarplus.ca under AltaGas' profile or at:

https://altagas.ca/invest/share-information/noticeandaccess

A request to receive AltaGas' annual financial statements is included in the form of proxy accompanying this notice.

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HOW TO OBTAIN PAPER COPIES OF THE MEETING MATERIALS

Shareholders may request that a paper copy of the Meeting Materials be sent to them by postal delivery at no cost. Requests may be made up to one year from the date the Meeting Materials were filed on SEDAR+ by calling:

1-866-962-0498

If you request Meeting Materials before the meeting, such materials will be sent to you at no cost within 3 business days of receiving your request. To receive Meeting Materials before the voting deadline specified in the form of proxy, your request must be received no later than April 15, 2025. Please note that you will not receive another form of proxy, so please keep the one you received with this notice.

If you request Meeting Materials on or after the date of the Meeting, such materials will be sent to you within 10 calendar days of receiving your request. Following the Meeting, the documents will remain available on SEDAR+ indefinitely and will remain available on the website listed above for a period of one year.

VOTING

There are several convenient ways to vote your shares in advance, including

• visiting www.investorvote.com
• scanning the QR code on your form of proxy with your smartphone
• mailing your completed form of proxy in the business reply envelope provided
• calling the toll-free number on your form of proxy

Along with this notice, you will find your form of proxy containing detailed instructions on how to vote your shares. You will need the control number printed on your form of proxy to complete the voting.

For additional instructions on how to vote your shares, refer to "How do I Vote my Shares?" in the Circular and, if voting online, the "Virtual Meeting User Guide" provided to you with this notice.

Shareholders are reminded to review the Circular prior to voting.

BOARD RECOMMENDATION

The Board of Directors of AltaGas recommends that shareholders VOTE FOR all of the proposed resolutions.

Please submit your vote well in advance of the proxy deposit deadline of 1:30 p.m. (MDT) on April 29, 2025.

If you have any questions with respect to voting your shares before the proxy deposit deadline, please contact AltaGas' proxy solicitation agent:

North American Toll-Free Number: 1-888-777-1639, Outside North America collect: 1-289-695-3075

Email: assistance@investor.sodali.com