ATP Plans to Sell Interests in Selected Assets

ATP Oil & Gas Corporation (NASDAQ:ATPG) today announced that it has engaged Scotia Waterous (USA) Inc. to assist in the sale of a portion of its working interests in certain producing and undeveloped properties in the Gulf of Mexico and U.K. North Sea. The company is preparing sales information and a data room for qualified bidders.

ATP plans to offer working interests in a number of its holdings, consisting of properties which together constitute approximately 80% of the pre-tax PV-10 value of ATP’s total proved plus probable reserves, including its deepwater producing Gomez Hub (MC 711 and MC 755), the emerging hub at Telemark (MC 941/942 and AT 63), and U.K. properties at Tors, Wenlock and Cheviot. ATP intends to continue to serve as the operator of each of its properties after the sale of partial working interests.

ATP Chairman and President T. Paul Bulmahn stated, “We believe material value has been created by our successful execution of development activities at ATP’s offshore hubs and we will continue to execute on the development of our extensive inventory of reserves. These sales of property interests will allow us to put some of that substantial value where it most benefits our shareholders.”

About ATP Oil & Gas Corporation

ATP Oil & Gas is an international offshore oil and gas development and production company with operations in the Gulf of Mexico and the North Sea. The company trades publicly as ATPG on the NASDAQ Global Select Market. For more information about ATP Oil & Gas Corporation, visit www.atpog.com.

Forward-looking Statements

Certain statements included in this news release are “forward-looking statements” under the Private Securities Litigation Reform Act of 1995. ATP cautions that assumptions, expectations, projections, intentions, or beliefs about future events may, and often do, vary from actual results and the differences can be material. Some of the key factors which could cause actual results to vary from those ATP expects include changes in natural gas and oil prices, the timing of planned capital expenditures, availability of acquisitions, uncertainties in estimating proved reserves and forecasting production results, operational factors affecting the commencement or maintenance of producing wells, the condition of the capital markets generally, as well as our ability to access them, and uncertainties regarding environmental regulations or litigation and other legal or regulatory developments affecting our business. The SEC has generally permitted oil and gas companies, in filings made with the SEC, to disclose only proved reserves that a company has demonstrated by actual production or conclusive formation tests to be economically and legally producible under existing economic and operating conditions. We and our independent third party reservoir engineers use the terms “probable” and “possible” and we use the term “recoverable hydrocarbons” to describe volumes of reserves potentially recoverable through additional drilling or recovery techniques that the SEC’s guidelines may prohibit us from including in filings with the SEC. These estimates are by their nature more speculative than estimates of proved reserves. All estimates of probable and possible reserves in this news release have been prepared by our independent third party engineers and all estimates of recoverable hydrocarbons have been prepared by management. More information about the risks and uncertainties relating to ATP’s forward-looking statements are found in our SEC filings.