Royal Dutch Shell Plc (RDSA) and Canadian oil and gas company Nexen Inc. (NXY) said Friday they made a significant new offshore oil discovery in the eastern Gulf of Mexico.

Shell made the discovery in the
Appomattox prospect, drilling in more than 7,000 feet of water. The companies didn't release an estimate of the amount of reserve discovered, but said they planned to drill appraisal wells to measure the resource later this year.

It's the third oil discovery Shell and Nexen have made in the deepwater eastern gulf since 2003.

Shell is the operator of the
Appomattox project, and owns an 80% stake, while Nexen, based in Calgary , owns a 20% interest.

Nexen shares rose 2.9% in recent premarket trading to $24.25