X0304 4 2011-08-12 0000314808 Ensco plc ESV 0001075947 SWENT JAMES W III 6 CHESTERFIELD GARDENS 3RD FLOOR LONDON X0 W1J 5BQ UNITED KINGDOM 0 1 0 0 Senior Vice President & CFO American Depositary Shares 2011-08-12 4 F 0 1798 46.79 D 109977 D The reporting person disposed of these shares directly to the issuer upon the vesting of previously awarded restricted stock. The purpose of the disposition was to enable the reporting person to satisfy tax withholding obligations that arose upon such vesting, which will be paid by the issuer to the Internal Revenue Service in cash. /s/ Elizabeth Wright, by Power of Attorney 2011-08-16