X0304 4 2012-03-02 0000314808 Ensco plc ESV 0001495170 Knowlton John Stokes 500 N. AKARD STREET SUITE 4300 DALLAS TX 75201-3331 0 1 0 0 Sr. Vice President - Technical American Depositary Shares 2012-03-02 4 F 0 997 57.12 D 64943 D The reporting person disposed of these shares to an affiliate of the issuer upon the vesting of previously awarded restricted shares. 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 2012-03-06