ATP Resumes Production at Telemark Hub; Continues Workover Operation on MC 941 A-2

ATP Oil & Gas Corporation

today announced that it has resumed production at the ATP Titan platform which services the company's Telemark Hub. Production from the ATP Titan, shut-in since May 14, resumed after the operator of the Mars pipeline temporarily shut in the pipeline to allow for the tie-in of a new offsetting platform which has now been completed. Production at the ATP Titan is proceeding as expected and will ramp up over the next few days. ATP also announced that it has completed perforation at the lower B sand at the Mississippi Canyon (MC) 941 A-2 well, part of the Telemark Hub, and operations to frac-pac have commenced. Work on the MC 941 A-2 well is expected to be completed before the end of June, 2012 and the well will be placed on production immediately. The MC 941 Block produces through the ATP Titan floating drilling and production platform. ATP operates the ATP Titan and Telemark Hub which is in approximately 4,000 feet of water with a 100% working interest and holds a 100% ownership in ATP Titan LLC which owns the ATP Titan and associated pipelines and infrastructure.