 In 1983, Ogunlesi joined the investment bank First Boston as an advisor on a Nigerian gas project.At First Boston, he worked in the Project Finance Group, advising clients on transactions and financings and has worked on transactions in North and South America, the Caribbean, Europe, the Middle East, Africa and Asia.From 1997 to 2002, he was the Head of the Global Energy Group of the by then renamed Credit Suisse First Boston (CSFB).