ATP Begins 2008 with Record Reserves and Production

ATP Oil & Gas Corporation record reserves in all categories, an annual production increase of 26% and a reserve replacement ratio of 223%.

ATP reported independent third-party year-end 2007 total proved plus probable reserves of 181.7 MMBoe with a pre-tax PV-10 value of approximately $5.3 billion. Proved reserves were 119.3 MMBoe, an increase of 13.1 MMBoe (+12%), with a pre-tax PV-10 value of approximately $3.5 billion. Equally important was the growth in proved developed reserves, increasing 5.7 MMBoe (+16 %) to 41.3 MMBoe. ATP's 181.7 MMBoe of proved and probable reserves are located 57% in the Gulf of Mexico Deepwater, 4% on the Gulf of Mexico Shelf and 39% in the North Sea.

ATP achieved a 223% reserve replacement ratio for 2007 with additions of 23.8 MMBoe to its proved reserves. Acquisitions resulted in 5.2 MMBoe, while revisions, extensions and discoveries to properties previously owned accounted for 18.6 MMBoe. ATP coupled these additions with record production of 10.7 MMBoe, including 8.6 MMBoe in the Gulf of Mexico and 2.0 MMBoe in the North Sea.

ATP's 2006 and 2007 proved and probable reserve reports were prepared by independent third-party reservoir engineers. ATP's Gulf of Mexico reserves were prepared by Ryder Scott Company, L.P., Collarini Associates and DeGolyer and MacNaughton. ATP's U.K. reserves were prepared by RPS Energy and ATP's Netherlands reserves were prepared by Ryder Scott Company, L.P.

The proved reserve quantities and classifications contained in the reports prepared by the independent third-party reservoir engineers conform to the definition as set forth in accordance with parameters established by the Securities and Exchange Commission ("SEC") Regulation S-X Part 210.4-10 (a) as clarified by subsequent Commission Staff Accounting Bulletins.