Royal Dutch Shell has invited binding bids from companies including Grangemouth refinery owner Ineos and Blackstone-backed Siccar Point Energy for the sale of some of its North Sea assets worth about $2 billion, according to a Bloomberg report.

Energy explorer Chrysaor Holdings has teamed up with private equity firm EIG Global Energy Partners to submit a second-round bid, the report said.

Shell is said to be selling a number of UK North Sea assets including its stake in the Buzzard oil field.

“Shell is continually evaluating its portfolio and is in contact with other parties regarding potential portfolio opportunities,” the company told Bloomberg.

“We have previously stated that a review of all assets, including those in the North Sea, is underway as part of our commitment to sell $30 billion of assets.”