TAMA Transmission - Enters Alberta to bid on the Fort McMurray West Transmission Project

CALGARY, ALBERTA--(Marketwired - May 9, 2013) - TransAlta Corporation (TSX:TA) (NYSE:TAC) and MidAmerican Transmission today announced the creation of a new strategic partnership, TAMA Transmission.

TAMA Transmission combines TransAlta's strength in power generation and long operating history in Alberta, with MidAmerican Transmission's and its parent company MidAmerican Energy Holdings Company's success and vast experience in transmission development, construction, operations and maintenance in North America. The creation of TAMA Transmission builds on an existing successful relationship with the TAMA Power partnership.

"TransAlta's core market is Alberta, where we've supplied electricity to wholesale and retail customers for over a hundred years. By combining our home market expertise with MidAmerican's superb construction management and operating skills, we believe we can win the right to serve Albertans with competitive, low-cost and reliable transmission infrastructure," said Dawn Farrell, TransAlta president and CEO.

This announcement signals TAMA Transmission's intention to participate in the Alberta Electric System Operator's competitive bid process to become the developer, owner and operator of the Fort McMurray West Transmission Project. The project is being developed to support Alberta's critical transmission infrastructure.

"MidAmerican Transmission, through this new Canadian partnership, looks forward to the opportunity to participate in this process to help unlock the significant value the Fort McMurray West Transmission Project can bring to Alberta. We are well-positioned to provide cost-effective transmission solutions to customers based on our experience with delivering large complex projects into service on time and within budget commitments," said Greg Abel, MidAmerican Energy Holdings Company chairman, president and CEO.

Development of the Fort McMurray West Transmission Project is necessary to meet the growth of that area of the province, and will also help oil sands development, one of the big contributors to Alberta's and Canada's economies, to continue at pace. The competitive process gives new players, like TAMA Transmission, a fair opportunity to enter the transmission market. The process also brings competitive pressures to bear on transmission costs and helps ensure the project's timely completion.

Cynthia Johnston will serve as the president of TAMA Transmission. Ms. Johnston has 27 years of electric industry experience in Alberta, including senior executive roles at TransAlta and FortisAlberta Inc.

To view the backgrounder associated with this release, click the following link: http://media3.marketwire.com/docs/ta_bg.pdf

TransAlta

TransAlta has been operating in Alberta for over 100 years and helped build and operate Alberta's original transmission infrastructure. As an area where TransAlta already has expertise, transmission is a natural fit with its operating model. Learn more about TransAlta at www.transalta.com .

TransAlta is a power generation and wholesale marketing company focused on creating long-term shareholder value. TransAlta maintains a low-to-moderate risk profile by operating a highly contracted portfolio of assets in Canada, the United States and Australia. TransAlta's focus is to efficiently operate geothermal, wind, hydro, natural gas and coal facilities in order to provide customers with a reliable, low-cost source of power. For over 100 years, TransAlta has been a responsible operator and a proud contributor to the communities in which it works and lives. TransAlta has been selected by Jantzi-Sustainalytics as one of Canada's Top 50 Socially Responsible Companies since 2009 and is recognized globally for its leadership on sustainability and corporate responsibility standards by FTSE4Good. TransAlta is Canada's largest investor-owned renewable energy provider.

MidAmerican Transmission

MidAmerican Transmission, a wholly owned subsidiary of MidAmerican Energy Holdings Company, based in Des Moines, Iowa, is engaged in the development of electric transmission facilities. MidAmerican Transmission has invested in transmission in several regions in the U.S. and is evaluating opportunities to further develop electric transmission facilities in organized and traditional markets in the U.S. and Canada. Additional information about MidAmerican Transmission is available at www.midamericantransmission.com .

Through its subsidiaries, MidAmerican Energy Holdings Company provides electric and natural gas service to more than 7 million customers worldwide, operates an extensive 18,000-mile electric transmission system, a natural gas local distribution system, and interstate natural gas pipeline systems totaling nearly 17,000 miles. Learn more at www.midamerican.com .

This news release may contain forward-looking statements, including statements regarding the business and anticipated financial performance of TransAlta Corporation. These statements are based on TransAlta Corporation's belief and assumptions based on information available at the time the assumption was made. These statements are subject to a number of risks and uncertainties that may cause actual results to differ materially from those contemplated by the forward-looking statements. Some of the factors that could cause such differences include legislative or regulatory developments and general economic conditions in geographic areas where TransAlta Corporation operates.