US banking giant Citigroup announced Tuesday that Vikram Pandit had resigned as chief executive and a member of the board of directors. The board unanimously elected Michael Corbat, manager of the bank\'s business in Europe, the Middle East and Africa, to succeed Pandit. The unexpected announcement came a day after Citigroup, the country\'s third largest bank, reported an 88 percent drop in earnings for its third quarter. Pandit said Citigroup had emerged from the 2008 financial crisis as a strong institution. \"Given the progress we have made in the last few years, I have concluded that now is the right time for someone else to take the helm at Citigroup,\" he said in a statement. Pandit called Corbat the \"right person\" to succeed him, with a 29-year record of achievement and leadership at the company. Citi\'s president and chief operating officer, John Havens, also resigned. Havens said he had planned to retire at year-end but decided to leave the company in light of Pandit\'s resignation. On Monday, Citigroup reported an 88 percent drop in quarterly earnings, hit by heavy one-time charges. Citi shares dropped 2.2 percent to $35.85 in pre-market trade in New York following the Pandit announcement.