Citigroup Inc. Chairman and Chief Executive Charles Prince, beset by the company's billions of dollars in losses from investing in bad debt, has resigned and is being replaced as chairman by former U.S. Treasury Secretary Robert Rubin.

The United States' largest banking company announced Prince's widely expected departure Nov. 4, following a meeting of its board. Citi also said Sir Win Bischoff, chairman of Citi Europe and a Member of the Citi management and operating committees, would serve as interim CEO.

Rubin, a former co-chairman of Goldman, Sachs & Co., has served as the chair of Citi's executive committee, and was expected to take a greater role in leading the company.