TransAlta responds to Directors' Circular filed by Canadian Hydro Developers

CALGARY, ALBERTA--(Marketwire - Aug. 6, 2009) - TransAlta Corporation TA TAC provided the following comment in response to the Directors' Circular filed earlier today by Canadian Hydro Developers, Inc. "Canadian Hydro provided very little new information today to support its recommendation to shareholders that they should reject our all-cash offer," said Steve Snyder, President and CEO of TransAlta. "Our offer represents a significant premium on top of the value that the market had already assigned to Canadian Hydro before our bid. We recognize the quality of Canadian Hydro's assets, including its people, growth opportunities, and environmental attributes, and these were fully considered by us before our bid." TransAlta's all-cash offer represents a premium of 30 per cent over the $3.50 volume weighted average closing trading price of the Canadian Hydro common shares over the 10 trading days immediately prior to July 20, 2009. The offer will remain open until 6:00 p.m. (Mountain) on August 27, 2009 unless withdrawn or extended. TransAlta strongly encourages shareholders of Canadian Hydro Developers to read the offer and circular, which contain the full terms and conditions of the offer as well as detailed instructions on how shareholders can tender their common shares to the offer. Copies of the offer and circular and related documents are also available online at www.transalta.com. Canadian Hydro Developers shareholders electing to tender their common shares to the offer must complete the letter of transmittal or, if necessary, the notice of guaranteed delivery (both of which accompany the offering circular) and return the appropriate document in accordance with the terms and conditions more fully set out under ''Manner of Acceptance'' in Section 3 of the offer. If common shares of Canadian Hydro Developers are held in the name of a nominee, such as a broker, investment dealer, bank or trust company, the shareowner should contact such nominee for instructions on how to deposit their common shares to the offer. For assistance in tendering shares to the TransAlta offer, Canadian Hydro Developers shareholders are encouraged to contact Georgeson Shareholder Communications Canada Inc. at 1-866-783-6752 (North American Toll Free Number) or 1-212-806-6859 (Bank, Brokers and collect calls). TransAlta is a power generation and wholesale marketing company focused on creating long-term shareholder value. We maintain a low to moderate risk profile by operating a highly contracted portfolio of assets in Canada, the United States, and Australia. Our focus is to efficiently operate our coal-fired, gas-fired, hydro and renewable facilities in order to provide our customers with a reliable, low-cost source of power. For nearly 100 years, we've been a responsible operator and a proud contributor to the communities where we work and live. TransAlta is recognized for its leadership on sustainability by the Dow Jones Sustainability North America Index, the FTSE4Good Index and the Jantzi Social Index. Reader Advisory This news release may contain statements that constitute "forward-looking information" or "forward-looking statements" (collectively "forward-looking information") within the meaning of applicable securities legislation. This forward-looking information is subject to numerous risks and uncertainties, certain of which are beyond TransAlta's control including, without limitation, uncertainty related to the completion of the offer to acquire Canadian Hydro Developers and the effects of the transaction in the event it is completed on TransAlta, the impact of legislative or regulatory developments, competition, global capital markets activity, changes in prevailing interest rates, currency exchange rates, inflation levels and general economic conditions in geographic areas where TransAlta operates. Readers are cautioned that the foregoing list of risk factors is not exhaustive. Additional information on these and other factors that could affect TransAlta's results are included in reports on file with the Canadian and United States securities regulatory authorities. TransAlta's actual results, performance or achievements may differ materially from those expressed in, or implied by this forward-looking information and, accordingly, no assurance can be given that any events anticipated by the forward-looking information will transpire or occur, or if any of them do so, what benefits that TransAlta will derive therefrom. Forward-looking information is based on the estimates and opinions of TransAlta's management at the time the information is released and TransAlta does not undertake any obligation to update publicly or to revise any of the forward-looking statements, whether as a result of new information, future events or otherwise, except as may be required by applicable securities laws. This news release does not constitute an offer to sell or the solicitation of an offer to buy any securities. No offering of securities will be made absent registration under, or an exemption from the registration requirements of, applicable securities laws. Note: All financial figures are in Canadian dollars unless noted otherwise.