ATP Oil & Gas Corporation (NASDAQ: ATPG) will host a live conference call on Thursday, May 10 th at 11:00 am CDT to discuss the company’s first quarter results followed by a Q&A session. ATP expects to issue a press release announcing first quarter results before the market opens on Thursday, May 10 th. 1 st Quarter Results Conference Call Date: Thursday, May 10, 2012 Time: 12:00 pm EDT; 11:00 am CDT; 10:00 am MDT and 9:00 am PDT ATP invites interested persons to listen to the live webcast on the company’s website at www.atpog.com. Phone participants may dial 888-259-8885. A digital replay of the conference call will be available at 888-203-1112, ID# 2370475, for a period of 24 hours beginning at 3:00 pm CDT. 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, Mediterranean Sea and 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.