Lehman Brothers executed a sudden management shake-up Thursday, ousting its long-serving president and demoting its finance chief following a $2.8bn Q2 loss that raised questions about its future as an independent investment bank. Joe Gregory, president since 2004, will be replaced by Bart McDade, head of Lehman’s equities division, while Erin Callan, who became Wall St’s top woman when she took over as finance chief in December, will be replaced by Ian Lowitt, co-chief administrative officer. Callan, once seen as a potential chief executive, will return to the investment banking division, for now. The shake-up came a day after Lehman’s share price fell another 13.6% to $22.70, well below the discounted $28 price paid by investors who took part in a $6bn capital-raising announced Monday. Separate analysis here.