Vikram Pandit, Apr. 29, 2011 (Creative Commons).

According to the Wall Street Journal, Pandit and Citigroup president and chief operating officer John Havens both resigned after clashing with the board over the bank's performance and strategic planning. Citigroup named Mike Corbat as its new CEO.

Pandit assumed the top job at Citigroup in December 2007, on the eve of the global financial crisis. Citi managed to survive the Wall Street crash, but Pandit has taken criticism over a nearly $3 billion write-down stemming from a Morgan Stanley brokerage deal as well as the relatively poor performance of the company's stock.

After recently leading Citigroup to a very strong quarter, with its stock surging 5 percent in Monday's trading, there would seem to be no performance-based urgency to make such a dramatic move. As Yahoo News reports, Pandit had been taking a salary of $1 for years, mainly as a PR move, and a dispute over compensation may have been a factor in Tuesday's move.

News of Pandit's sudden departure shocked Wall Street insiders and Citigroup staffers, some of whom found out on their Bloomberg terminals before receiving the firm's internal memo.

"We respect Vikram's decision," Chairman Michael E. O'Neill said. "Since his appointment at the start of the financial crisis until the present time, Vikram has restructured and recapitalized the company, strengthened our global franchise and refocused the business."

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