Exxon Mobil is considering an exit from the British North Sea after more than 50 years in the oil and gas basin as it focuses on U.S. shale production and new projects.

The world’s largest publicly traded energy company, Exxon has held talks with a number of North Sea operators in recent weeks to gauge interest in some or all of its assets, which could fetch up to $2 billion, according to three industry sources with knowledge of the matter.

Exxon declined to comment, according to Reuters.

Leaving the British North Sea would mark a major retreat from Europe for Irving, Texas headquartered Exxon, which has already put its Norwegian offshore assets on the block.

It would follow similar moves by U.S. rivals Chevron and ConocoPhillips which earlier this year sold the bulk of their North Sea operations.

Most of Exxon’s operations are managed through a 50-50 joint venture with Royal Dutch Shell, known as Esso Exploration and Production UK, and include interests in nearly 40 oil and gas fields.

Shell declined to comment.