On 20 July 2010, Ensco Offshore Company, a subsidiary of Ensco plc ("Ensco"), filed an amended complaint in the U.S. District Court for the Eastern District of Louisiana in New Orleans against the U.S. Department of the Interior, the U.S. Bureau of Ocean Energy Management, Regulation and Enforcement and other defendants seeking a declaration that the defendants violated the U.S. Administrative Procedures Act and the Outer Continental Shelf Lands Act. In addition to the relief requested in the original complaint filed on 9 July 2010, the amended complaint addresses (1) the actions taken by the U.S. Department of the Interior on 12 July 2010 to impose a second moratorium/suspension on deepwater drilling in the U.S. Gulf of Mexico and (2) documentary and permitting requirements with respect to both shallow and deep water drilling and related activities in the U.S. Gulf of Mexico that lack proper legislative, regulatory or procedural authorization. The lawsuit continues to seek a more well-defined regulatory process for instituting new safety measures and operational and permitting requirements for U.S. Gulf of Mexico shallow and deep water offshore drilling so as to comply with the U.S. Administrative Procedures Act and the Outer Continental Shelf Lands Act, inter alia. A copy of the amended complaint is furnished as Exhibit 99.1 to this report and incorporated herein by reference.