Citigroup (NYSE: C) is considering putting all or part of the company up for sale. It is easy to say that the reason is the drop in its share price or a loss of customer confidence. It may not be that simple. The bank's stock has dropped as low as $4.39 yesterday. Five trading days before that, they were over $10.

Across the Atlantic, Barclays (NYSE: BCS), one of the world's largest banks, is trying to raise just over $10 billion to replenish is capital base. Next Monday, shareholders vote on whether or not to authorize the plan. Some observers believe that the firm will lose the vote and its finances will be pushed into in limbo. According to The Wall Street Journal, "If Barclays loses the vote, it could face a challenging time in raising capital." Much of the money is already lined up to come from Qatar and Abu Dhabi

Citi's board of directors may believe that their company could face a similar trial. There is no clear indication that the Treasury will put more money into the bank, although it might do that if Citi appeared to be in a liquidity crisis. But, the cost of that cash might be the bank's independence. The federal government might insist on a deal like the one the Fed has with AiG (NYSE: AIG) which nearly wiped out common shareholders. If Citi decides to go to the market for money, it may struggle to be successful

There is no question. Citigroup is watching the Barclays shareholder vote and knows that the outcome is far from guaranteed to be in the UK bank's favor.

Douglas A. McIntyre is an editor at 24/7 Wall St.