X0303 5 2010-12-31 0 0 0000314808 Ensco plc ESV 0001193406 CHADWICK WILLIAM S JR 500 N. AKARD STREET SUITE 4300 DALLAS TX 75201-3331 0 1 0 0 Executive Vice President & COO American Depositary Shares 2010-12-31 5 A 0 .2777 39.95 A 12.054 I Ensco Savings and Retirement Plans Amount is representative of Ensco American Depositary Shares acquired, and held indirectly, via the Ensco Savings and Retirement Plans as of December 31, 2010. Amount is representative of Ensco American Depositary Shares acquired, and held indirectly, through normal payroll contributions to the Ensco Savings and Retirement Plans for the months of January through December 2010. Price of Securities dependent upon trading price applicable on date of future transactions. The average cost/price is representative of all benefically, indirectly owned securities acquired via normal payroll contributions to the Ensco Savings and Retirement Plans. /s/ William S. Chadwick, Jr. 2011-01-18