By Jon Stempel and Dan Wilchins
NEW YORK (Reuters) - CITIGROUP (C.NY)Inc
Shares of Citigroup initially rose more than 6 percent in premarket trading following the news, but later they gave up those gains and were down 2 percent.
The shares tumbled 23 percent on Wednesday to a 13-year low as investors questioned the survival prospects of the U.S. banking giant.
"Spreads are widening on pretty much everything," said Keith Davis, a bank analyst at Farr, Miller & Washington. "Given that backdrop, how much capital is Citi going to need to shore up their balance sheet? I don't think anyone knows, and so the knee-jerk reaction is to sell first and ask questions later."
In a statement, Alwaleed said he believes the shares are "dramatically undervalued" following a nearly 90 percent plunge since late 2006. Citigroup's market value was $34.9 billion on Wednesday, meaning that Alwaleed plans to invest at least $349 million, based on Wednesday's closing price.
Alwaleed expressed "full and complete support to Citi management," including embattled Chief Executive Vikram Pandit.
He said the New York-based bank is "taking all the necessary steps to position the company to withstand the challenges facing the banking industry and the global economy."
Alwaleed added that he is "fully confident that Citigroup's universal banking model and global franchise will make it a long-term winner in the financial services industry."
The prince's percentage stake in the bank was reduced in late 2007 and early 2008 as Citigroup raised some $50 billion of capital from sovereign wealth funds and other investors, including Alwaleed, to shore up its balance sheet. It recently received another $25 billion under the U.S. government's bank bailout package.
Shares of Citigroup have fallen 78 percent this year. They lost one-third of their value in the first three days of this week as investors worried that Pandit's plan to cut expenses by 20 percent and eliminate 52,000 jobs won't restore the bank to health.
Citigroup has lost $20.3 billion in the last year and taken tens of billions of dollars of writedowns on mortgage and other toxic debt. Analysts expect it to lose money in the fourth quarter, and some don't expect it to be profitable in 2009.
Pandit suffered a major setback last month when Wells Fargo & Co
(Additional reporting by Elinor Comlay and Jonathan Spicer; writing by Christian Plumb; editing by John Wallace)