BP is again seeking buyers for its stake in the Shearwater oil field in the British North Sea after talks with Royal Dutch Shell fell through, industry and banking sources said.

The talks between Shell, the field’s operator, and BP failed due to disagreement over the value of the 27.5% stake, the sources said.

Industry sources estimated the stake was worth $250 million when Reuters first reported on the talks in April.

Shell holds a 28% stake in Shearwater, while Exxon Mobil Corp. has the remaining 44.5%.

Shell and BP declined to comment.

Ariel Flores, BP’s North Sea boss, told reporters in Aberdeen this week that the company wanted to focus on developing the Eastern Trough Area Project (ETAP) hub, located north of Shearwater.

“You can’t do it all in the central North Sea,” Flores said, when asked about BP’s thinking on Shearwater.

Shearwater, 225 km (140 miles) east of Aberdeen, was discovered in 1988 and first developed in 2000. At peak production, the gas export capacity of the Shearwater hub is expected to be around 400 million standard cubic feet per day, or roughly 70,000 barrels of oil equivalent per day, according to Shell.

Shell announced plans last year to expand a gas hub around Shearwater, including the construction of a new pipeline.