AtkinsRéalis Group Inc. — Proxy Solicitation & Information Statement 2026

Apr 14, 2026

AtkinsRéalis

Computershare

320 Bay Street, 14th Floor

Toronto, ON M5H 4A6

www.computershare.com

Security Class

Shareholder Account Number

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Form of Proxy - Annual Meeting to be held on May 14, 2026

This Form of Proxy is solicited by and on behalf of Management.

Notes to proxy

1. Every shareholder has the right to appoint a proxyholder of their choice to attend and act on their behalf at the annual meeting of shareholders (the "Meeting") of AtkinsRéalis Group Inc. (the "Company") or any adjournment or postponement thereof. If you wish to appoint a proxyholder other than the Management Nominees whose names are printed herein, please insert the name of your chosen proxyholder in the space provided (see reverse).
2. This form of proxy should be signed by the shareholder(s) in the exact manner as the name(s) appear(s) on the form of proxy. If the securities are registered in the name of more than one owner (for example, joint ownership, trustees, executors, etc.), then all those registered should sign this form of proxy. If you are voting on behalf of a corporation or another individual, you may be required to provide documentation evidencing your power to sign this form of proxy with signing capacity stated. A person or company acting as proxyholder need not be a shareholder of the Company. If you are voting on behalf of a corporation you are required to provide your name and designation of office, e.g., ABC Inc. per John Smith, President.
3. If a date is not inserted in the space provided on the reverse of this form of proxy, it will be deemed to bear the date on which it was mailed to the shareholder by Management.
4. The securities represented by this form of proxy will be voted as directed by the shareholder. However, if such a direction is not made in respect of any matter, and the form of proxy appoints the Management Nominees listed on the reverse, this form of proxy will be voted as recommended by the Board of Directors and Management.
5. The securities represented by this form of proxy will be voted in favour, or withheld from voting, or voted against each of the matters described herein, as applicable, in accordance with the instructions of the shareholder, on any ballot that may be called for. If you have specified a choice with respect to any matter to be acted on, the securities will be voted accordingly.
6. This form of proxy confers discretionary authority in respect of amendments or variations to matters identified in the Notice of Meeting and Management Proxy Circular or other matters that may properly come before the Meeting or any adjournment or postponement thereof, unless prohibited by law.
7. This form of proxy should be read in conjunction with the accompanying documentation provided by Management.

Poxies submitted must be received by 11:00 am, Eastern Daylight Time, on May 12, 2026.

VOTE USING THE TELEPHONE OR INTERNET 24 HOURS A DAY 7 DAYS A WEEK!

To Vote Using the Telephone

• Call the number listed BELOW from a touch tone telephone.
  1-866-732-VOTE (8683) Toll Free

To Vote Using the Internet

• Go to the following web site: www.investorvote.com
• Smartphone? Scan the QR code to vote now.

To Receive Documents Electronically

• You can enroll to receive future shareholder communications electronically by visiting www.investorcentre.com.

To Virtually Attend the Meeting

• You can attend the Meeting virtually by visiting the URL provided on the back of this form of proxy.

If you vote by telephone or the Internet, DO NOT mail back this form of proxy.

Voting by mail or by Internet are the only methods by which a shareholder may appoint a person as proxyholder other than the Management Nominees named on the reverse of this form of proxy. Instead of mailing this form of proxy, you may choose one of the two voting methods outlined above to vote this form of proxy.

To vote by telephone or the Internet, you will need to provide your CONTROL NUMBER listed below.

CONTROL NUMBER

02550C

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Appointment of Proxyholder

I/We, being shareholder(s) of AtkinsRéalis Group Inc. (the “Company”) hereby appoint: William L. Young (Chair of the Board) or, failing him Ian L. Edwards (President and Chief Executive Officer) or failing him Geneviève Simard (Vice-President and Corporate Secretary),

OR

Print the name of the person you are appointing if this person is someone other than the Management Nominees listed herein.

Note: If completing the appointment box above YOU MUST go to http://www.computershare.com/ATRL and provide Computershare with the name and email address of the person you are appointing. Computershare will use this information ONLY to provide the appointee with a user name to gain entry to the hybrid meeting.

as my/our proxyholder with full power of substitution and to attend, act and to vote for and on behalf of the shareholder in accordance with the following direction (or if no directions have been given, as the proxyholder sees fit) and on all other matters that may properly come before the Annual Meeting of Shareholders of the Company (the “Meeting”) to be held on May 14, 2026 at 11:00 am Eastern Daylight Time, in person at Lumi Experience - 1250 René-Lévesque Blvd West, Suite 3610, Montréal, Québec, H3B 4W8, and by live webcast at https://meetings.lumiconnect.com/400-383-329-387 as well as at any adjournment or postponement thereof.

VOTING RECOMMENDATIONS ARE INDICATED BY HIGHLIGHTED TEXT OVER THE BOXES.

The Board of Directors and Management recommend that shareholders VOTE FOR items 1, 2, 3, and 4. The Board of Directors recommends that shareholders VOTE AGAINST items 5, 6 and 7 below:

1. Election of Directors

	For	Against		For	Against		For	Against
01. Gary C. Baughman	☐	☐	02. Mary-Ann Bell	☐	☐	03. Christie J.B. Clark	☐	☐
04. Ian L. Edwards	☐	☐	05. Nathalie Marcotte	☐	☐	06. Ruby McGregor-Smith	☐	☐
07. Robert Paré	☐	☐	08. Michael B. Pedersen	☐	☐	09. Sam Shakir	☐	☐
10. Benita M. Warmbold	☐	☐	11. William L. Young	☐	☐

1. Appointment of Independent Auditor Appointment of Deloitte LLP as Independent Auditor.

2. Amended and Restated Shareholder Rights Plan Agreement

3. Non-binding Advisory Vote on the Company's Approach to Executive Compensation

4. Shareholder Proposal No. 1 – Schedule B to the Management Proxy Circular.

5. Shareholder Proposal No. 2 – Schedule B to the Management Proxy Circular.

6. Shareholder Proposal No. 3 – Schedule B to the Management Proxy Circular.

	For	Against
For	☐	☐
For	☐	☐
For	☐	☐

Authorized Signatory(ies)

I/We authorize you to act in accordance with my/our instructions set out above. I/ We hereby revoke any instructions previously given with respect to the Meeting. If no voting instructions are indicated above, and the proxy appoints the Management Nominees, the securities will be voted as recommended by the Board of Directors and Management. If you are voting on behalf of a corporation you are required to provide your name and designation of office, e.g., ABC Inc. per John Smith, President.

Signature(s)

Date

DD/MM/YY

Signing Capacity

Interim Financial Statements – Mark this box if you would like to receive interim financial statements and Management's Discussion and Analysis by mail.

☐ Annual Financial Statements – Mark this box if you would like to receive the Annual Financial Statements and accompanying Management's Discussion and Analysis by mail.

☐ Management Proxy Circular – Mark this box if you would like to receive the Management Proxy Circular by mail for the next shareholders meeting.

If you are not mailing back your proxy, you may register online to receive the above financial report(s) by mail at www.computershare.com/mailinglist.

SNCQ

390452

AR1

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02551D