X0303 4 2010-05-25 1 0000314808 Ensco plc ESV 0001198575 CARMICHAEL DAVID M 500 N. AKARD STREET SUITE 4300 DALLAS TX 75201-3331 1 0 0 0 American Depositary Shares 2010-05-25 4 J 0 12320 38.99 A 12320 D Non-Employee Director Stock Option (Right to Buy) 50.28 2010-05-25 4 J 0 4500 50.28 A 2006-06-01 2013-06-01 American Depositary Shares 4500 4500 D Non-Employee Director Stock Option (Right to Buy) 60.74 2010-05-25 4 J 0 4500 60.74 A 2007-06-01 2014-06-01 American Depositary Shares 4500 4500 D No changes in benefical ownership of securities have taken place. This filing has been accomplished to reflect the total beneficial ownership of Ensco securities at retirmement from the Ensco Board of Directors on May 25, 2010. Amount is representative of all beneficially owned American Depositary Shares and All Non-Employee Director Restricted Stock Grants, which vested on May 25, 2010, at retirement from the Ensco Board of Directors. Amount is representative of a Non-Employee Director Stock Option, which was fully vested at grant date, and outstanding on May 25, 2010 at retirement from the Ensco Board of Directors. The Non-Employee Director Stock Option is exerciable until June 1, 2013. Amount is representative of a Non-Employee Director Stock Option, which was fully vested at grant date, and outstanding on May 25, 2010 at retirement from the Ensco Board of Directors. The Non-Employee Director Stock Option is exerciable until June 1, 2014. /s/ Robert O. Isaac, by Power of Attorney 2010-05-26