Mumbai: Citigroup Inc, the largest US bank, said it will raise at least $14.5 billion and cut its quarterly dividend 41 per cent to help shore up a capital base depleted by an $18.1 billion write-down in subprime mortgage and consumer credit related losses.

The $18.1 billion write-down includes $17.4 billion in collateralised debt obligations.

Citi also reported an overall fourth quarter loss of $9.83 billion, or $1.99 per share - its first quarterly loss since its inception in 1998 - after the write-downs and a $4.1 billion increase in US credit costs.

Citigroup also cut its quarterly dividend to 32 cents per share from 54 cents, a move that could save it more than $4 billion a year.

Citigroup said it would raise $12.5 billion from a private sale of convertible preferred securities, including $6.88 billion from a Singapore-affiliated fund, chief executive Sanford Weill and his family foundation, Saudi Prince Alwaleed bin Talal, the Kuwait Investment Authority, the money manager firm Capital Research & Management, and the state of New Jersey.

The bank will also sell $2 billion of convertible preferred securities to other investors, and sell additional preferred securities.

"We are taking comprehensive action to position Citi for the future with the capital strength that will allow us to refocus on earnings and earnings growth," Vikram Pandit, chief executive, said in a statement.

Mounting credit losses and cost overruns led to the November departure of Charles Prince as chief executive, and Pandit's elevation the following month.

Pandit joined Citigroup in July when the bank bought his hedge fund firm, Old Lane Partners LP, for $800 million.

Citigroup also in December brought billions of dollars of structured debt onto its balance sheet, after the plan to create a "super-SIV" to help sell those securities foundered.

The bank's Tier 1 capital ratio now stands lower at 7.1 per cent, down from 7.32 per cent on September 30, though above the 6 per cent regulatory requirement.