John Browne, one of Britain's highest-profile businessmen, stepped down as chief executive of BP after details of his relationship with a gay partner became public.

Browne, 59, resigned after a U.K. court ruled that a British newspaper can publish details of his private life.

Browne may face perjury charges for lying to the High Court about the original circumstances under which he met his former partner, a Canadian named Jeff Chevalier. In a statement, Browne admitted he made "untruthful" statements about his relationship.

He is accused of misusing company funds on Chevalier, treating him to the same lavish lifestyle enjoyed by one of Britain's most successful executives. He is also charged with sharing sensitive information with Chevalier, including BP strategy and details about conversations with British prime minister Tony Blair.

Some of Browne's alleged misappropriations include paying for a university course to extend Chevalier's visa, and providing BP resources to help Chavalier set up a company trading in mobile phone ring tones. After Chevalier's return to Canada, Browne also allegedly paid to lease and furnish a Toronto apartment for him.

Browne denies the accusations. 

The couple's 2006 split apparently became acrimonious when Browne turned down Chevalier's repeated requests for financial assistance and Chevalier took his story to the press.

Browne's departure is effective immediately, and he will forfeit $7 million of his retirement package and possibly another $24 million.

Browne, who had expected to leave BP in July, will become non-executive chairman of the supervisory board at U.K. buyout firm Apax Partners. He will be replaced at BP by Tony Hayward, who is currently head of exploration and production.

On Tuesday, shares of BP closed down 2.50 pence to 563 pence a share on the London Stock Exchange.