Endeavour International Corp. said it agreed to acquire ConocoPhillips's interest in three producing U.K. oil fields in the Central North Sea for $330 million, including about $94 million in tax attributes, building on Endeavor's North Sea holdings.

Current net production from the assets is about 10,000 barrels of oil equivalent per day, and Endeavor estimates that proved and probable reserves there as of June were more than 33 million barrels of oil equivalent.

Endeavor Chief Executive William L. Transier said the new assets will generate a large increase in cash flow for the company. They also add to the company's two existing U.K. development projects, which are estimated to start production during 2012, he said.

Earlier this month, Endeavor said it terminated its agreement to purchase Marcellus shale assets from SM Energy Co., which rebuked the move as unauthorized. The deal was expected to expand Endeavour's position in the shale oil and gas-producing region.

Last month, Endeavour reported that its loss widened sharply during the third quarter on charges related to tax changes in the U.K. and the discontinuation of activities in Alabama, as well as production interruptions.

Endeavor's shares closed Friday $6.40, while ConocoPhillips's shares closed at $72.43. Both stocks were inactive premarket.

Tags: Endeavour International Corporation