ATP Prices Secondary Stock Offering

ATP Oil & Gas has priced a public offering of 5,000,000 shares of its common stock at $47.00 per share to the public. ATP is required, under the terms of its existing credit agreement, to remit approximately $56 million (or 25%) of the net proceeds from the offering to its lenders to prepay term loans under the credit agreement. Each lender has the right to reject its share of the mandatory prepayment, and any declined proceeds must then be reoffered to those lenders that have accepted their share of the mandatory prepayment; ATP may retain any remaining declined proceeds. ATP intends to use the remaining net proceeds from the offering to fund capital expenditures related to its drilling and development activities, including a potential second MinDOC at its Telemark Hub and potential new wells at Wenlock, Canyon Express Hub and Green Canyon Block 37, and for general corporate purposes. Howard Weil Incorporated and Johnson Rice & Company L.L.C. acted as joint book-running managers for the offering.

The underwriters have been granted by Chairman and President of ATP, T. Paul Bulmahn, a 30-day option to purchase up to an additional 750,000 shares of ATP's common stock at the public offering price less the underwriting discount to cover over-allotments, if any. Assuming the underwriters' full exercise of the over-allotment option, Mr. Bulmahn will own approximately 17.6% of ATP's common stock after the offering. ATP will not receive any proceeds from the sale of shares by Mr. Bulmahn.

The offering is expected to close on November 20, 2007, subject to customary closing conditions. The common stock will be issued pursuant to an effective shelf registration statement previously filed with the Securities and Exchange Commission.