Citigroup Inc., the fourth-largest American home lender by new loan volume, plans to pare its American residential unit’s mortgage and home-equity holdings by about $45 billion, or 20%, over the next year.

The Citigroup division will decrease its total holdings mainly by making fewer loans that can’t be sold, the president of CitiMortgage Inc., Bill Beckmann, said in a telephone interview yesterday. The assets will drop as existing loans are repaid, he said.

“We will look for opportunistic sales, but we’re not counting on that, considering current market conditions,” Mr. Beckmann said. Citigroup plans to be selling about 90% of the home loans that the company makes through his unit by the third quarter, up from 65% last year, according to a statement yesterday.

The New York-based bank’s plan will further cut financing available to American borrowers, as investors flee even government-guaranteed mortgage bonds. Lenders including Wells Fargo & Co. and Countrywide Financial Corp. have already restrained direct home lending, depressing prices for mortgage securities and making it more costly for consumers to obtain loans.

“For a long time there was a lot of cash sloshing around the markets, and that cash has dissipated,” an analyist of asset-backed securities at Wachovia Corp.’s Tattersall Advisory Group, Darcy Morrison, said in an interview yesterday. “Banks aren’t writing mortgages faster than they can breathe anymore.”

Citigroup’s move reflects the chief executive officer Vikram Pandit’s push to commit the company’s balance sheet only to assets producing higher returns, Mr. Beckmann said in the interview. Pressure on the company’s capital ratios from the credit market contraction are speeding a reduction in mortgage holdings that would have occurred eventually anyway, he said.

The largest American bank by assets posted a record loss of $9.8 billion in the fourth quarter. It raised $7.5 billion in November from Abu Dhabi and said in January it was getting another $14.5 billion from investors including the governments of Singapore and Kuwait. The company will probably report a loss again in the first quarter, according to analysts at Merrill Lynch & Co. and Goldman Sachs Group Inc.

Citigroup yesterday also said it will save $200 million within 12 months as a result of the merger of its various American mortgage businesses. The combination was announced in January. Mr. Beckmann declined to say how many jobs would be cut.