TransAlta Announces Commercial Paper Program.

Business Editors

CALGARY, Alberta--(BUSINESS WIRE)--May 13, 2004

TransAlta Corporation (NYSE:TAC)(TSX:TA) has restructured its Canadian commercial paper program (the "Program"). A maximum of $200 million of short-term notes may be issued and outstanding under the Program at any time. Notes will be issued by TransAlta and guaranteed by TransAlta Utilities Corporation ("TAU"), a wholly-owned subsidiary of TransAlta. The obligations guaranteed by TAU rank equally with its secured debentures.

Notes issued under the Program have been rated R-1 (low) by Dominion Bond Rating Service.

The securities offered have not been and will not be registered under the Securities Act of 1933, as amended, and may not be offered or sold in the United States absent registration or an applicable exemption from registration requirements.

All currency is expressed in Canadian dollars except where noted.

TransAlta is among Canada's largest non-regulated power generation and wholesale marketing companies. We have coal-fired, gas-fired, hydro and renewable generation assets in Canada, the U.S., Mexico and Australia. With approximately 10,000 megawatts of capacity either in operation, under construction or in development, our focus is to efficiently operate our assets in order to provide our wholesale customers with a reliable, low-cost source of power.