Reuters news agency said ExxonMobil had held talks with North Sea operators in recent weeks to gauge interest in some or all of its assets, citing three industry sources it did not identify.
The portfolio could fetch up to $2 billion (£1.7bn). ExxonMobil could use the proceeds to help fund investment in major projects in the US and in Guyana, where it has made big finds.
US majors Chevron and ConocoPhillips have sold big North Sea portfolios in recent months in order to shift investment to shale fields in their home country.
The ExxonMobil portfolio could attract interest from the likes of Chrysaor Energy and Neptune Energy. Both have built big North Sea businesses through acquisitions with backing from international private equity investors.
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ExxonMobil has interests in around 40 oil and gas fields in the UK North Sea including the Shearwater hub east of Aberdeen. Many of these are operated by Shell under the Esso Exploration and Production venture.
On its website ExxonMobil says it is one of the largest investors in the U.K.’s offshore oil and gas industry, having invested around £32.6bn in today’s prices since starting exploration work in 1964.
The firm says it is responsible for approximately five per cent of UK oil and gas production, supplying an average of 80,000 barrels of oil and 441 million cubic feet of gas a day.
ExxonMobil and Shell did not comment on the report.
Neivan Boroujerdi, principal analyst, North Sea upstream, at oil and gas consultancy Wood Mackenzie, noted: “A proposed UK exit was expected. We value the portfolio at around US$2 billion.”
ExxonMobil put its Norwegian North Sea operations up for sale in June.