Ineos has confirmed it is in talks with ConocoPhillips over a potential acquisition of the US oil and gas giant’s stake in the North Sea’s Clair oilfield. According to UK press reports, the deal could be worth as much as $3 billion.

While the Swiss-based chemical group did not provide additional details, Conoco has labeled the talks “exclusive.” A company spokesman told UK business newspaper Financial Times (FT), however, that any potential deal for its British assets would not include the Teeside oil terminal or London.

The oil group, like other US competitors, is gradually withdrawing from the North Sea to concentrate on US shale exploration at home. Conoco has already done an asset swap with BP, selling a 16.5% holding in the Clair field to BP in exchange for a 39.2% stake in Alaska’s Greater Kuparuk oilfield. Conoco’s remaining stake was 7.5% following conclusion of the BP deal, but talks about a new deal reportedly concern only a 6.5% stake.

Citing “people familiar with the sale process,” told the FT said Ineos had paid a “substantial” deposit to give it exclusivity over the talks for three months, as it feared competition from other buyers including private equity companies are playing a growing role in the North Sea.

Two private equity investors are said to be have expressed interest in Conoco’s latest asset sale.