X0303 4 2008-09-26 0000891456 PLAINS EXPLORATION & PRODUCTION CO PXP 0000939485 FLORES JAMES C 700 MILAM SUITE 3100 HOUSTON TX 77002 1 1 0 0 Chairman of the Board Common Stock 2008-09-26 4 P 0 165400 35.57 A 165400 I By limited partnership Common Stock 2008-09-26 4 P 0 101146 36.58 A 266546 I By limited partnership Common Stock 2008-09-26 4 P 0 13454 37.08 A 280000 I By limited partnership Common Stock 196 I By 401(k) plan. Common Stock 1605333 D This price is the weighted average of the shares purchased. Actual prices ranged from $35.01 to $35.99. This price is the weighted average of the shares purchased. Actual prices ranged from $36.06 to $37.02. This price is the weighted average of the shares purchased. Actual prices ranged from $37.03 to $37.16. Upon request by the SEC staff, PXP, or a security holder of PXP, full information regarding the number of shares purchased at each price will be provided. By Flores, L.P., a limited partnership, controlled by reporting person as general partner. The information in this report is based on a plan statement dated as of June 30, 2008. Deborah R. Anderson, as attorney-in-fact for James C. Flores 2008-09-29