The continuing fall in Citigroup (NYSE: C - News) 's share price on Friday fuelled speculation that the company would have to change its strategic direction or its management.

Vikram Pandit, Citi's chief executive, tried to reassure employees that he had no plans to break up the company. But the crisis was leading investors and regulators to consider ways in which the giant US financial group could be helped.

The fall in Citi's share price - which has shaved off more than half its market value this week - suggested investors were not satisfied by Citi's assertions it had ample capital and liquidity.

"The problem is not capital but confidence, and as a financial institution, confidence is just about everything," said Pri de Silva, analyst at CreditSights.

Potential strategic options for Citi include a fire-sale, a break-up, or even a government takeover of the company, analysts say.

With more than $2,000bn in assets on its balance sheet and another $850bn in assets to which it has some connection, Citi's sheer size could make it tough for any one buyer to absorb.

Purchase accounting rules would require the buyer to write down Citi's assets to market prices, which could result in a hit of more than $100bn, said Mr de Silva. Few, if any, acquirers would be willing to take that kind of hit to their capital without government assistance.

Larger US rival JPMorgan could also be precluded from buying the entire bank because of regulatory limits on the pool of US deposits any one institution can control. That might not be an obstacle, however, for aforeign bank such as HSBC or Santander.

One potential scenario would be a split of the company, which some investors have lobbied for in the past.

Citi's well-regarded overseas operations could draw interest from JPMorgan and other banks, according to people close to Citi. Its US deposit base might look appetising to Goldman Sachs, which has already held a loose conversation with Citi about a deal. Citi's US deposits could also, alternatively, be split among stronger US commercial banks such as US Bancorp, PNC or Wells Fargo.

Both PNC and Wells Fargo are in the midst of acquisitions that may limit theportion of Citi they would want to buy.

Potential buyers for Citi's investment banking and credit card operations were less clear. Other banks are paring back their investment banking operations and shying away from consumer credit risks as the economy weakens.

Sales of business lines would likely be cash deals, however, as acquirers would be reluctant to use stock for anything short of a purchase of all of Citi.

As potential buyers have little cash to spare, analysts said Citi may have to provide financing to any buyer, which would limit the benefit to its shareholders and may only be a short-term solution for the bank.

People close to the matter stressed, however, that any speedy break-up scenario would almost certainly have to come with the support of the US government.

Several people close to the bank felt that rather than a sale right now, the most likely scenario would be for the government to step in and buy a large slug ofpreferred stock that would make it Citi's largest shareholder, as is now the case with AIG, Fannie Mae (NYSE: FNM - News) and Freddie Mac.

Citi was closely monitoring its liquidity position on Thursday and Friday. Two people close to the bank said they had heard no reports any large customers had pulled away from the bank's cash management business, a key component of its global operations.

"Their big issue is going to be liquidity, and it's the cash management business that matters the most," one person with knowledge of the matter said.

The fall in Citi's share also presents a significantchallenge for Mr Pandit, who has been widely criticised on Wall Street. Mr Pandit's town hall meeting onMonday, in which he announced no new initiatives, disappointed some senior Wall Street executives.

Some said Mr Pandit's performance reminded them of the way Dick Fuld, the chief executive of Lehman Brothers, conducted himself as Lehman's share price fell. "He [Mr Pandit] has waited way too long to break up the bank," says the co-founder of one private equity firm.

Citi shares were down 18.2 per cent at $3.72 in mid-afternoon trading on Friday in New York.