Citigroup Inc may need to raise additional capital despite the U.S. government's move to bolster its capital base, said an analyst at Deutsche Bank, who sees a 2009 loss of about $4.5 billion for the company excluding any preferred share dividend payments.

There is still a good chance that Citi will be required to raise additional capital, possibly due to demands from regulators or simply due to its deteriorating credit quality and balance sheet, analyst Mike Mayo wrote in a note to clients.

The U.S. government said on February 27 it will boost its equity stake in Citigroup to as much as 36 percent through the conversion of up to $25 billion in preferred shares to common stock. This was the third attempt by the government to prop up Citigroup in the past five months.

There is unusual uncertainty related to capital needs, normalized earnings, and operating mode with new government ownership that make any investment in Citi stock an abnormally risky one that could just as easily see its stock double as it could get significantly reduced, Mayo said.

He estimates that Citigroup will suffer a cumulative loss of $85 billion on a lifetime basis, given expected loan losses of $65 billion and capital market write-downs of $20 billion.

He maintained his hold rating on Citigroup shares and has a price target of $3.

The analyst said his target reflects uncertainty in the bank's earnings prospects over the next two years.

(Reporting by Tenzin Pema in Bangalore; Editing by Gopakumar Warrier)