Alan Brown, group chief investment officer at State Street Global Advisors and one of the most influential figures in fund management, has resigned while his internal rival for the top job has been promoted, the company said.
Brown has not confirmed his next step but sources close to him said it was widely expected he would jump to a hedge fund, although others close to him said he could take time off or move into policymaking.
The news comes shortly after SSgA's Brown was passed over for the top job.
In January, the bank named 42-year-old William Hunt as chief executive of SSgA after the death of Timothy Harbert last year.
Brown stepped in as acting co-chief executive alongside Peter Leahy after the death of Harbert before Hunt joined but both are understood to have applied for the top role.
Brown, however, after missing out on the permanent appointment received a bonus pot worth up to 200% of his base salary for his troubles, to be paid in 2006.
Leahy has since been promoted to executive vice president and is now responsible for State Street's global alliance companies and client sales and strategy in addition to his former role as chief operating officer.
Brown's role overseeing the three CIOs is to be divided among the team, according to SSgA. He had been promoted to group CIO in 2001, after joining the company in 1995. The spokeswoman said it was business as normal. Sources said the departure had been friendly.