TransAlta Corporation (TransAlta or the Company) (TSX: TA; NYSE: TAC) announced today that 1,824,620 of its 12,000,000 Cumulative Redeemable Rate Reset Preferred Shares, Series A (the €œSeries A Shares) have been converted, on a one-for-one basis, into Cumulative Redeemable Floating Rate Preferred Shares, Series B (the €œSeries B Shares). As a result of the conversion, TransAlta has 10,175,380 Series A Shares and 1,824,620 Series B Shares issued and outstanding.

The Series B Shares will begin trading on the Toronto Stock Exchange (TSX) today under the symbol TA.PR.E. The Series A Shares will continue to be listed on the TSX under the symbol TA.PR.D.

About TransAlta Corporation

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 wind, hydro, solar, 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 recognized on CDP’s Canadian Climate Disclosure Leadership Index (CDLI), which includes Canada’s top 20 leading companies reporting on climate change, and has been selected by Corporate Knights as one of Canada’s Top 50 Best Corporate Citizens and is recognized globally for its leadership on sustainability and corporate responsibility standards by FTSE4Good.

For more information about TransAlta, visit our web site at transalta.com, or follow us on Twitter @TransAlta.

For more information:

Investor Inquiries:

Jaeson Jaman
Manager, Investor Relations
Phone: 1-800-387-3598 in Canada and U.S.
Email: [email protected]

Media Inquiries:

Roman Cooney
Managing Director, Communications
Toll-free media number: 1-855-255-9184
Email: [email protected]

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CALGARY, Alberta August 10, 2012 TransAlta Corporation (TSX:TA) (NYSE:TAC) today announced it has completed its public offering of 9,000,000 Cumulative Redeemable Rate Reset First Preferred Shares, Series E (the €œSeries E Shares) at a price of $25.00 per Series E Share.

The offering, previously announced on August 2, 2012, resulted in gross proceeds to TransAlta of $225 million. The net proceeds of the offering will be used to partially fund capital projects, for other general corporate purposes, and to reduce short term indebtedness of the Corporation and its affiliates.

The Series E Shares were offered to the Canadian public through a syndicate of underwriters led by CIBC, RBC Capital Markets and Scotiabank by way of a prospectus supplement that was filed with securities regulatory authorities in Canada under TransAlta’s short form base shelf prospectus dated November 15, 2011.

Holders of Series E Shares are entitled to receive a cumulative quarterly fixed dividend yielding 5.00% annually for the initial period ending September 30, 2017. Thereafter, the dividend rate will be reset every five years at a rate equal to the 5-year Government of Canada bond yield plus 3.65%. Holders of Series E Shares will have the right, at their option, to convert their shares into Cumulative Redeemable Rate Reset First Preferred Shares, Series F (the €œSeries F Shares), subject to certain conditions, on September 30, 2017 and on September 30 every five years thereafter. Holders of Series F Shares will be entitled to receive cumulative quarterly floating dividends at a rate equal to the three-month Government of Canada Treasury Bill yield plus 3.65%. The Series E Shares are listed on the Toronto Stock Exchange under the ticker symbol TA.PR.H.

About TransAlta Corporation

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 our wind, hydro, geothermal, natural gas and coal facilities in order to provide our customers with a reliable, low-cost source of power. For 100 years, TransAlta has 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. TransAlta is Canada’s largest investor-owned renewable energy provider.

This news release may contain forward looking statements, including statements regarding the business and anticipated financial performance of TransAlta Corporation. In particular, this news release includes forward-looking statements relating to the public offering of the Series E Shares and the expected use of proceeds therefrom. 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, pricing in the market place, our inability to enter into long term contracts due to prevailing market conditions, legislative or regulatory developments, competition, global capital markets activity, changes in interest rates, currency exchange rates, inflation levels and general economic conditions in geographic areas where TransAlta Corporation operates.

Note: All financial figures are in Canadian dollars unless noted otherwise.

For more information:

Investor and Media Inquiries:

Jess Nieukerk
Director, Investor Relations
Phone: 1 800-387-3598 in Canada and U.S.
Email: [email protected]

TransAlta Corporation (TSX:TA) (NYSE:TAC) today announced it has completed its public offering of 11,000,000 Cumulative Redeemable Rate Reset First Preferred Shares, Series C (the “Series C Shares”) at a price of $25.00 per Series C Share.

The offering, previously announced on November 22, 2011, resulted in gross proceeds to TransAlta of $275 million. The net proceeds of the offering will be used to partially fund capital projects, for other general corporate purposes, and to reduce short term indebtedness of the company and its affiliates. TransAlta may invest funds that it does not immediately require in short term marketable debt securities.

The Series C Shares were offered to the Canadian public through a syndicate of underwriters led by CIBC World Markets Inc., RBC Capital Markets and Scotia Capital Inc. by way of a prospectus supplement that was filed with securities regulatory authorities in Canada under TransAlta’s short form base shelf prospectus dated November 15, 2011.

Holders of Series C Shares are entitled to receive a cumulative quarterly fixed dividend yielding 4.60% annually for the initial period ending June 30, 2017. Thereafter, the dividend rate will be reset every five years at a rate equal to the 5-year Government of Canada bond yield plus 3.10%. Holders of Series C Shares will have the right, at their option, to convert their shares into Cumulative Rate Reset First Preferred Shares, Series D (the “Series D Shares”), subject to certain conditions, on June 30, 2017 and on June 30 every five years thereafter. Holders of Series D Shares will be entitled to receive cumulative quarterly floating dividends at a rate equal to the three-month Government of Canada Treasury Bill yield plus 3.10%. The Series C Shares are listed on the Toronto Stock Exchange under the ticker symbol TA.PR.F.

About TransAlta Corporation

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 our geothermal, wind, hydro, natural gas and coal facilities in order to provide our customers with a reliable, low-cost source of power. For 100 years, TransAlta has 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. TransAlta is Canada’s largest investor-owned renewable energy provider.

This news release may contain forward looking statements, including statements regarding the business and anticipated financial performance of TransAlta Corporation. In particular, this news release includes forward-looking statements relating to the public offering of the Series C Shares and the use of the proceeds therefrom. 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, competition, global capital markets activity, changes in prevailing interest rates, currency exchange rates, inflation levels and general economic conditions in geographic areas where TransAlta Corporation operates.

Note: All financial figures are in Canadian dollars unless noted otherwise.

For more information:

Media Inquiries:

Glen Whelan
Director, Communications
Phone: (403) 267-7287
Email: [email protected]

Investor Inquiries:

Jess Nieukerk
Director, Investor Relations
Phone: 1 800-387-3598 in Canada and U.S.
Email: [email protected]

TransAlta Corporation (TSX:TA) (NYSE:TAC) today announced it has completed its public offering of 10,000,000 Cumulative Rate Reset First Preferred Shares, Series A (the €œSeries A Shares). In addition, the full option granted to the syndicate of underwriters led by CIBC World Markets Inc., RBC Dominion Securities Inc. and Scotia Capital Inc., as bookrunners, was exercised for an additional 2,000,000 Series A Shares also at a price of $25.00 per Series A Share.

The offering, previously announced on December 2, 2010, resulted in gross proceeds to TransAlta of Cdn $300 million. The net proceeds of the offering will be used to partially fund capital projects, for other general corporate purposes and to reduce short term indebtedness of the company and its affiliates, which short term indebtedness was used to fund TransAlta’s capital program and for general corporate purposes. TransAlta may invest funds that it does not immediately require in short term marketable debt securities.

The Series A Shares were offered to the public in Canada through the underwriters or their affiliates by way of a prospectus supplement that was filed with securities regulatory authorities in Canada under TransAlta’s short form base shelf prospectus, which was previously filed with securities regulatory authorities in Canada.

Holders of Series A Shares are entitled to receive a cumulative quarterly fixed dividend yielding 4.60% annually for the initial period ending March 31, 2016. Thereafter, the dividend rate will be reset every five years at a rate equal to the 5-year Government of Canada bond yield plus 2.03%. Holders of Series A Shares will have the right, at their option, to convert their shares into Cumulative Rate Reset First Preferred Shares, Series B (the €œSeries B Shares), subject to certain conditions, on March 31, 2016 and on March 31 every five years thereafter. Holders of Series B Shares will be entitled to receive cumulative quarterly floating dividends at a rate equal to the three-month Government of Canada Treasury Bill yield plus 2.03%. The Series A Shares are listed on the Toronto Stock Exchange under the ticker symbol TA.PR.D.

About TransAlta Corporation

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 our biomass, geothermal, wind, hydro, natural gas and coal facilities in order to provide our customers with a reliable, low-cost source of power. For 100 years, TransAlta has 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. TransAlta is Canada’s largest investor-owned renewable energy provider.

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, competition, global capital markets activity, changes in prevailing interest rates, currency exchange rates, inflation levels and general economic conditions in geographic areas where TransAlta Corporation operates.

Note: All financial figures are in Canadian dollars unless noted otherwise.

For more information:

Media Inquiries:

Bob Klager
Director, Public Affairs
Phone: (403) 267-7330 or Email: [email protected]

Investor Inquiries:

Jess Nieukerk
Director, Investor Relations
Phone: 1 800-387-3598 in Canada and U.S.
Email: [email protected]