Tony Hayward, the former BP chief executive, is to sever his ties to a Russian-backed venture which has struggled to gain British and American government approval to buy oil and gas assets.
Sky News has learnt that Mr Hayward, who left BP in the aftermath of the Deepwater Horizon disaster in 2010, is to step down as a member of the LetterOne (L1) Energy advisory board.
Sources close to L1 confirmed the departure of Mr Hayward, who now serves as chairman of the FTSE-100 mining and commodities trading giant Glencore.
A number of industry insiders suggested that the L1 Energy advisory board was being scaled back or disbanded because Dea, the German oil and gas group it acquired in 2015, had its own supervisory board which served a similar purpose.
The committee of L1 Energy advisers is led by Lord Browne, Mr Hayward’s predecessor as BP chief executive.
The two men have enjoyed a close professional relationship for decades, with Mr Hayward’s earlier BP roles including a stint as Lord Browne’s personal assistant.
L1 Energy’s advisory board also includes Andrew Gould, the former chairman of BG Group, Chip Goodyear, who ran the mining giant BHP Billiton, and Scott Sheffield, the chairman of Pioneer Natural Resources.
Sources said that a number of them could join the supervisory board of Dea in due course.
L1, which last month secured a £1.8bn deal to buy Holland & Barrett, the high street retailer, also has investment teams scouting for acquisitions in healthcare, telecoms and technology.
The group, which is based in Luxembourg, was established by Mikhail Fridman, a billionaire businessman who previously owned part of BP’s joint venture in Russia.
Since setting it up, Mr Fridman has overseen investments in companies such as Uber, the ride-sharing service.
In energy, however, L1 has encountered political resistance on both sides of the Atlantic.
The group pulled out of a deal to buy a Texan oil producer earlier this year amid reported concerns that it could fall foul of the US government panel which scrutinises overseas investments for potential national security risks.
L1 Energy also had to agree to sell a number of UK North Sea oilfields as part of its takeover of Dea, in response to demands from the then Energy and Climate Change Secretary, Ed Davey.
The Government had raised concerns about potential future Russian sanctions, a stance which angered Mr Fridman and his colleagues, who include Lord Davies, the former Trade Minister and one of the UK’s most widely respected businessmen.
A spokesman for L1 declined to comment on Mr Hayward’s impending departure from its energy unit advisory board, but told Sky News: “We are evolving L1 Energy’s approach as it is now well past the start-up phase.
“Dea is now in good shape, it’s refocused on five key countries and is a growth platform.
“Dea has its own supervisory board that acts as an investment advisory board and now has a greater international focus so is looking at opportunities in Mexico and elsewhere.”
Since the original Dea takeover, L1 Energy has added further assets through a deal with E.ON, the German energy group, which provided it with a platform to expand its Norwegian presence.
The company is now also funding projects in Egypt and Algeria, which L1 believes will support average annual production growth at Dea of approximately 15% between now and 2021.
Mr Hayward, meanwhile, is continuing to seek a sizeable oil deal in Latin America in conjunction with Carlyle, the private equity firm.
In April, he announced his departure from Genel Energy, a struggling Kurdistan-focused oil company which he founded in partnership with Nat Rothschild, the wealthy financier.
Mr Hayward could not be reached for comment on Wednesday.