Was It Money That Forced Pandit Out? 10:22 AM ET Tue, 16 Oct 2012

The shock change at the top of the bank came just one day after Citigroup posted surprisingly strong quarterly results. (Read: Pandit's Departing Memo to Employees )

There were reports, however, that Pandit had been clashing with the board over strategy and performance. The Wall Street Journal said the board was frustrated with the performance of the institutional clients unit, among other issues.

"A high-level person told me he was forced out last night, " said CNBC stock commentator Jim Cramer. (Read More: Pandit's Sudden Exit: What Really Happened?)

Pandit, however, denied that he was forced out, telling CNBC that "it was my decision." (Read More from Pandit Interview )

Pandit also resigned from the bank's board of directors, effectively immediately. President and Chief Operating Officer John Havens resigned as well.

Corbat was formerly the chief executive of Citi's Europe, Middle East, and Africa division. (Read More: Meet Citigroup's New Boss .)