An anonymous director reports

TRANSALTA ANNOUNCES CLOSING OF $350 MILLION BOUGHT DEAL OFFERING OF COMMON SHARES

TransAlta Corp. has closed its previously announced bought deal offering of common shares.

Pursuant to the offering, TransAlta issued a total of 18.23 million common shares at a price of $19.20 per share for total gross proceeds of approximately $350-million.

The offered shares were offered and sold through a syndicate of underwriters led by CIBC Capital Markets and RBC Capital Markets.

TransAlta intends to use the net proceeds of the offering to finance the cash purchase price of its previously announced acquisition of two new natural-gas-fired peaking facilities totalling 318 megawatts near Denver, Colo. The acquisition is expected to close early in the fourth quarter of 2026, subject to the satisfaction of certain closing conditions, including receipt of regulatory approvals.

The underwriters also have an option to purchase up to an additional 2,734,500 common shares at the offering price, exercisable for a period of 30 days following the closing of the offering, for potential additional gross proceeds to TransAlta of approximately $52,502,400.

If the acquisition is not completed, the company intends to use the net proceeds from the offering to finance future growth opportunities (including acquisitions), to finance its capital development expenditures, to reduce its outstanding indebtedness or for other general corporate purposes.

For additional information regarding the acquisition and the offering, refer to the company's news release dated June 3, 2026, available under TransAlta's profile on SEDAR+ and on EDGAR.

About TransAlta Corp.

TransAlta is one of Canada's largest publicly traded power generators, delivering reliable electricity across Canada, the United States and Western Australia. For more than 100 years, TransAlta's people have safely operated and evolved essential energy infrastructure that powers customers and communities. TransAlta's technology-diverse portfolio and disciplined execution allow the company to deliver dependable power across evolving energy systems. TransAlta takes a practical, responsible approach to meeting today's energy needs while building for what comes next.

We seek Safe Harbor.