Updated from 1:23 a.m. EDT

Ahead of Citigroup's ( C) investor meeting Tuesday, a report says senior officials at the Federal Deposit Insurance Corp. privately have discussed who might replace CEO Vikram Pandit if the bank needed more government aid.

"It is unthinkable that Vikram could stay on if Citi requires more federal funds," a person familiar with the matter said, the Financial Times reports. "It is prudent to be thinking about different scenarios."

The FDIC is one of the regulators that has a say on whether Pandit steps down if the government bails out the bank for the fourth time in six months following completion of the "stress test" of Citigroup's health, the newspaper notes. Any decision on Citigroup's leadership will be led by the Treasury Department, which is about to take a 36% stake in the bank and must approve further capital injections.

People close to the situation said FDIC officials had discussed successors to Pandit, who was named Citigroup CEO in December 2007.

The possible successors include Ned Kelly, chief financial officer; Gary Crittenden, his predecessor and chairman of the division containing Citigroup's non-core assets; and one of Citigroup's new board members. The new directors include: Jerry Grundhofer, former CEO of U.S. Bancorp ( USB); Michael O'Neill, former head of the Bank of Hawaii ( BOH); Anthony Santomero, former head of the Philadelphia Federal Reserve; and William Thompson, former co-head of bond group Pacific Investment Management.

The FDIC and the other agencies declined to comment for the Financial Times.

In a statement, Citigroup said: "Our recent quarterly results reveal the underlying strength of the franchise and Mr. Pandit's strategy at work to restore Citi to profitability."

Meanwhile, Japan's three megabanks on Monday submitted offers to buy Citigroup's Nikko Cordial Securities in the second round of bidding, people familiar with the matter told Dow Jones Newswires.

Sumitomo Mitsui Financial , Mitsubishi UFJ Financial ( MTU) and Mizuho Financial ( MFG) are bidding for the unit, the people said.

The Nikkei reported the price for Nikko Cordial could reach 400 billion to 500 billion yen.

Mitsubishi UFJ, Japan's largest banking group, is still the leading candidate, Dow Jones reports, but Sumitomo Mitsui, the third largest by assets, has emerged as a leading contender.