**FILE** Lord John Browne, the then Chief Executive Officer of BP Group addresses the media, in this March 24, 2005 file photo, at City Hall in Texas City, Texas. Former BP Chief Executive John Browne has made a return to the oil industry, taking up a senior position at one of the world's largest private equity funds just three months after his scandal-tainted departure from BP. In a surprise announcement Friday, Aug. 24, 2007 New-York based Riverstone Holdings LLC, a private equity firm specializing in the energy and power sectors, said it had appointed Browne as head of its European operations. (AP Photo/Tony Gutierrez, file)