ATP Discovers Additional Sands at Deepwater Telemark Hub.

HOUSTON -- ATP Oil & Gas Corporation (NASDAQ:ATPG) today announced that it has discovered additional pay sands at the Mirage Prospect located at Mississippi Canyon Block 941(MC 941) at ATP's deepwater Telemark Hub in the Gulf of Mexico. The MC 941 #3 well, located in approximately 4,000 feet of water, encountered more than 250 feet of logged net oil and gas pay, more than doubling the pre-drill estimates. The 7 5/8 inch casing has been set at 17,089 feet measured depth through the pay intervals. Mirage is one of the three Telemark Hub fields that will be tied back to the ATP Titan to be located at MC 941. ATP has a 100% WI and is the operator of the Telemark Hub.

Commenting on the announcement, ATP Chairman and CEO T. Paul Bulmahn stated, "ATP is exceptionally pleased with these initial results. Not only have we encountered the development sands at greater thicknesses than expected but we have logged other hydrocarbon-bearing sands that were not present in the original wells, beyond even what was discussed and projected at the ATP Titan post-christening breakfast update held on August 27th. These additional pay sands should lead to upgraded production and reserve estimates greater than currently booked in our third party reserve reports, and we were already predicting ATP's Telemark Hub is projected to more than double ATP's production beginning in 2010."

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 is found in our SEC filings.