<div id="readability-page-1"><div>CALGARY, AB, May 13, 2026 /CNW/ - ATCO Ltd. (TSX: ACO.X)ATCO Ltd. is pleased to announce the addition of Rona Ambrose to the Board of Directors. Ms. Ambrose, well known for her government and business leadership, is the newest of the nine ATCO board members elected at ATCO's Annual Meeting of Share Owners held on May 13, 2026.&#34;With her impressive background and extensive political, business and community experience, Ms. Ambrose brings considerable leadership and strategic insight to our Company,&#34; said Nancy Southern, Chair &amp; Chief Executive Officer of ATCO Ltd. &#34;Her proven track record in guiding complex projects will be a tremendous asset to the Board as we continue to advance our commitment to excellence, sustainability and growth.&#34;The Honourable Rona Ambrose is the former Leader of Canada's Official Opposition in the House of Commons and the former Leader of the Conservative Party of Canada. Ms. Ambrose is currently Deputy Chairwoman at TD Bank Group's Investment Bank, TD Securities and has served on several corporate and non-profit boards, including Andlauer Health Group, Manulife Financial, TransAlta Corp. and Coril Holdings Inc. among others. She is also the founder and Chair of the Council of Women CEOs. Additionally, Ms. Ambrose is part of the Senior Advisory Board of the Canadian Global Affairs Institute and the advisory board of the Canadian American Business Council and the Trilateral Commission.At the Annual Meeting of Share Owners of ATCO Ltd., a resolution was passed by ballot electing each of the following nine nominees proposed as a director of ATCO to hold office until the next Annual Meeting of Share Owners or until his/her successor is elected or appointed.<div><table><tbody><tr><td colspan="1" rowspan="1">NOMINEES</td><td colspan="1" rowspan="1">VOTES FOR</td><td colspan="1" rowspan="1">% IN FAVOUR</td></tr><tr><td colspan="1" rowspan="1">Rona H. Ambrose</td><td colspan="1" rowspan="1">11,542,320</td><td colspan="1" rowspan="1">100 %</td></tr><tr><td colspan="1" rowspan="1">Jason T. Kenney</td><td colspan="1" rowspan="1">11,542,320</td><td colspan="1" rowspan="1">100 %</td></tr><tr><td colspan="1" rowspan="1">Kelly C. Koss-Brix</td><td colspan="1" rowspan="1">11,542,320</td><td colspan="1" rowspan="1">100 %</td></tr><tr><td colspan="1" rowspan="1">Robert J. Peabody</td><td colspan="1" rowspan="1">11,542,320</td><td colspan="1" rowspan="1">100 %</td></tr><tr><td colspan="1" rowspan="1">Robert J. Routs</td><td colspan="1" rowspan="1">11,542,320</td><td colspan="1" rowspan="1">100 %</td></tr><tr><td colspan="1" rowspan="1">Nancy C. Southern</td><td colspan="1" rowspan="1">11,542,320</td><td colspan="1" rowspan="1">100 %</td></tr><tr><td colspan="1" rowspan="1">Linda A. Southern-Heathcott</td><td colspan="1" rowspan="1">11,542,320</td><td colspan="1" rowspan="1">100 %</td></tr><tr><td colspan="1" rowspan="1">Norman M. Steinberg</td><td colspan="1" rowspan="1">11,542,320</td><td colspan="1" rowspan="1">100 %</td></tr><tr><td colspan="1" rowspan="1">Susan R. Werth</td><td colspan="1" rowspan="1">11,542,320</td><td colspan="1" rowspan="1">100 %</td></tr></tbody></table></div>This matter is described in greater detail in the Corporation's Management Proxy Circular dated March 6, 2026. A full report of voting results is available on SEDAR+ at www.sedarplus.ca.As a global enterprise ATCO Ltd. and its subsidiary and affiliate companies have approximately 20,000 employees and assets of $28 billion. ATCO is committed to future prosperity by working to meet the world's essential energy, housing, security and transportation challenges. ATCO Structures designs, builds and delivers products to service the essential need for housing and shelter around the globe. ATCO Frontec provides operational support services to government, defence and commercial clients. ATCO Energy Systems delivers essential energy for an evolving world through its electricity and natural gas transmission and distribution, and international electricity operations. ATCO EnPower creates sustainable energy solutions in the areas of electricity generation, energy storage, industrial water and cleaner fuels. ATCO Australia develops, builds, owns and operates energy and infrastructure assets. ATCO Energy provides retail electricity and natural gas services, home maintenance services and professional home advice that bring exceptional comfort, peace of mind and freedom to homeowners and customers. ATCO also has investments in ports and transportation logistics, the processing and marketing of ash, retail food services and commercial real estate. More information can be found at www.ATCO.com.Investor &amp; Analyst Inquiries:Colin JacksonSenior Vice President, Financial OperationsColin.Jackson@atco.com(403) 808 2636Media Inquiries:Kurt KadatzDirector, Corporate CommunicationsContact Media Relations(587) 228 4571Subscription Inquiries:To receive ATCO Ltd. news releases, please click here.SOURCE ATCO Ltd.</div></div>

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ATCO Ltd. has appointed Rona Ambrose to its Board of Directors during the Annual Meeting of Share Owners on May 13, 2026. Ambrose, a former Leader of Canada's Official Opposition and current Deputy Chairwoman at TD Securities, brings extensive leadership experience to the board. The election of Ambrose and eight other nominees was unanimously approved, reflecting the company's commitment to excellence and growth. ATCO Ltd. operates in various sectors, including energy, housing, and infrastructure, with a workforce of approximately 20,000 and assets totaling $28 billion.

Rona Ambrose joins ATCO's Board of Directors at AGM