X0306 4 2012-10-11 0 0001123647 ATP OIL & GAS CORP ATPG 0001218777 LONGNECKER BRENT M 4600 POST OAK PLACE SUITE 200 HOUSTON TX 77055 1 0 0 0 Common Stock 2012-10-11 4 J 0 48000 0 D 17710 D The reporting person transferred 48,000 shares to his ex-wife pursuant to a domestic relations order 7,000 shares held as Common Stock, 10,710 shares held as Restricted Stock Brent M. Longnecker 2012-10-12