Sky News has learnt that the FTSE 100 oil giant has enlisted Egon Zehnder International to identify a successor to Mr Looney.

Its search is expected to encompass external candidates as well as internal candidates, including the interim chief executive Murray Auchincloss.

Mr Auchincloss, who was previously BP's finance chief, has won broad support from shareholders to land the job on a permanent basis, according to City insiders.

The appointment process, however, is likely to take several months to conclude.

Mr Looney, whose payoff is still being determined by BP board members, had led the company since 2020.

In the statement announcing his resignation, BP said it had conducted two probes into his relationships with colleagues and that it had been given assurances during the first of those inquiries, which took place last year.

"Mr Looney has informed the company that he now accepts that he was not fully transparent in his previous disclosures," BP said in mid-September.

"He did not provide details of all relationships and accepts he was obligated to make more complete disclosure."

Shares in BP, which declined to comment, were trading on Wednesday at around 471.68p, giving it a market capitalisation of approximately £80bn.