ENSCO International Incorporated announced that one of its subsidiaries has entered into an agreement with the Keppel FELS Limited (Keppel FELS) Shipyard in Singapore to construct an ultra-deepwater semisubmersible rig to be named ENSCO 8503. The total project cost of ENSCO 8503 is currently estimated to be approximately $427 million, with delivery expected to be in the third quarter of 2010.

ENSCO 8503 is the Company's fourth semisubmersible rig in the ENSCO 8500 Series(TM). It will be the Company's fifth deepwater semisubmersible rig, joining the three other 8500 Series(TM) rigs and ENSCO 7500, which was delivered in 2000. The first three ENSCO 8500 Series(TM) rigs under construction by Keppel FELS, ENSCO 8500, ENSCO 8501 and ENSCO 8502, remain on schedule and on budget with expected deliveries in the second quarter of 2008, first quarter of 2009 and late fourth quarter 2009, respectively. ENSCO 8500 and ENSCO 8501 are both committed under long-term drilling contracts beginning upon delivery.

The ENSCO 8500 Series(TM) deepwater semisubmersibles are enhanced versions of ENSCO 7500, and are based upon an ENSCO proprietary design. The 8500 Series(TM) rigs will be capable of drilling in up to 8,500 feet of water, and can readily be upgraded to 10,000 feet water-depth capability if required. Enhancements include a two million pound quad derrick, offline pipe handling capability, increased drilling capacity, greater variable deck load, and improved automatic station keeping ability. With these features, the 8500 Series(TM) rigs will be especially well-suited for deepwater development drilling.

Daniel W. Rabun, ENSCO's Chairman, President and Chief Executive Officer, commented, "Today marks another milestone in our commitment to our strategic objective of expanding our deepwater fleet through our ENSCO 8500 Series(TM) proprietary design semisubmersible rigs. We are taking a balanced approach toward our objective of delivering long-term shareholder value by reinvesting in our business while, at the same time, addressing our capital structure by executing on our stock repurchase program. We continue to see strong demand for deepwater equipment and believe that our 8500 Series(TM) rigs are a cost-effective approach for addressing the growing deepwater market. We are gratified to again be working with Keppel FELS shipyard on the ENSCO 8503 project."