He was replaced by the bank's board by Michael Corbat, who had been Citigroup's CEO for Europe, Middle East and Africa.
John P. Havens, Citigroup's president and chief operating officer, also resigned.
Pandit took the CEO role in December 2007 and presided over the bank during the financial crisis and the slow recovery from it.
On Monday, Citigroup turned in surprisingly positive third-quarter results.
Other headlines this morning:
Goldman boosts profit. Investment bank Goldman Sachs' profit grew by nearly half in the third quarter spurred by debt underwriting, The Wall Street Journal reports.
PNC rides mortgages. PNC Financial, a new player in Charlotte, reported third quarter earnings up 11 percent driven by mortgage banking, Bloomberg says. Refinancings have been a bright spot for a number of banks, most notably Wells Fargo.
BofA reports tomorrow. Bank of America reports its third quarter results early Wednesday.