Lord Browne is leaving BP 18 months earlier than planned to devote more time to the private equity group, whose advisory board he joined last autumn.
After more than a decade in the chief executive officer role, Browne has decided to retire at the end of July 2007, a statement from BP said.
Tony Hayward, currently BP’s head of exploration and production, will replace Browne on August 1.
Peter Sutherland, BP’s chairman, said that Browne was due to stay as chief executive officer until the end of 2008.
During Lord Browne’s tenure as the chief executive of BP he has presided over a fivefold increase in the company’s market capitalisation to £104.6 billion (€159 million; $205 million) and profits to $22.3 billion.
Since 1995, more than 65 companies owned by Apax funds have been floated on public stock markets with a combined market capitalisation of $35 billion on listing, according to the buyout firm. It has offices in London, New York, Hong Kong, Mumbai and other European cities.