LONDON (Bloomberg) — John Browne stepped down as chief executive officer of BP Plc three months earlier than planned after losing a legal battle to prevent the publication of claims he let a former boyfriend use company resources.BP, Europe's second-biggest oil company, said yesterday in London that Tony Hayward, who was scheduled to replace Browne Aug. 1, takes over the position immediately. BP said allegations Browne misused resources were "unfounded or insubstantive".

Browne's decision follows a ruling by the High Court in London, released today, that he lied in his bid to block publication by the Mail on Sunday of the boyfriend's account of the four-year relationship. Browne, 59, built BP into what was once Europe's biggest company through more than $100 billion of acquisitions. In the past two years, he faced shareholder wrath over a deadly Texas refinery blast and oil leaks in Alaska.

"Hayward will no doubt drive the company forward as best he can," said Jason Kenney, an analyst with ING Wholesale Banking in Edinburgh. "I think it would be difficult for Lord Browne to be at the helm of BP and go through what's expected to be quite an investigative journalistic period."

Britain's highest court refused to hear Browne's bid for an order to prohibit the Mail on Sunday from printing its story, which centres on the executive's involvement with a Canadian named Jeff Chevalier. Both the High Court and the Court of Appeal had already rejected his case. Chevalier claimed Browne supported him with BP "resources and manpower," and that Browne paid him a "large sum of money" over their relationship, court documents said.

"In my 41 years with BP I have kept my private life separate from my business life," Browne said in yesterday's BP statement. "These allegations are full of misleading and erroneous claims. In particular, I deny categorically any allegations of improper conduct relating to BP."

Shares of BP slipped 0.4 percent to 563 pence in London.

Browne admitted that he had lied to court about how he first met Chevalier and that he later retracted and apologised for the untruthful account. He said in the statement that the decision to bring forward his retirement "is a voluntary step which I am making to avoid unnecessary embarrassment and distraction to the company at this important time".

Known as Lord Browne since being made a peer in 2001, he pushed ahead of his competitors in acquiring new supplies when BP formed a Russian joint venture with OAO Tyumen Oil Co., known as TNK-BP. Browne also fashioned BP as an environmentally friendly oil company, becoming the first CEO of a major oil producer to acknowledge global warming, ten years ago.

Hayward, 49, who was head of the company's exploration and production division, its biggest business unit, now takes over. A geology graduate of Edinburgh University in Scotland, Hayward joined BP in 1982 and after a succession of posts in France, China, Colombia and Venezuela, returned to London in 1997 as a director of BP Exploration. Two years later, he became a group vice president and was appointed to the board in 2003.

BP's first-quarter net income dropped 17 percent from a year earlier because of lower energy prices and a seventh consecutive quarter of year-on-year production declines, the company said April 24.