Colleagues who have traveled with Adebayo Ogunlesi during his years as a globe-trotting dealmaker have seen him face down bribe-seeking gunmen in his native Nigeria and effect a clever predawn escape from student rioters in Indonesia. But today Ogunlesi confronts a crisis that in many ways is scarier: he's the new head of worldwide investment banking at Credit Suisse First Boston (CSFB), which lost nearly $1 billion last year and faces accusations that its advice to investors was corrupted by its desire to please big corporate clients.
A standing ovation at his first staff meeting in February did not deter Ogunlesi,...