WASHINGTON — The government was moving ahead Wednesday on a fresh multibillion-dollar cash infusion to stabilize auto financing company GMAC Financial Services, according to a person with knowledge of the matter.

The person, who spoke on condition of anonymity because discussions weren't complete, says the government aid would range around $3 billion. That would be less than the roughly $6 billion the government had earlier thought GMAC would need to stabilize the company.

Shoring up GMAC has been a major component of the Obama administration's massive effort to rescue ailing automakers General Motors and Chrysler. The lender provides critical wholesale financing to thousands of GM and Chrysler auto dealers, allowing them to stock their showroom floors with vehicles. GMAC has already received $12.5 billion in taxpayer money and is 35 percent owned by the federal government.

But GMAC also operates a large residential mortgage business, ResCap, which was battered by the recent housing collapse. GMAC was obligated by the Treasury Department to raise $11.5 billion in additional capital earlier this year after failing the government's stress test for banks, largely because of ResCap's big losses. However, GMAC had difficulty raising money because of its financial woes, making an extra government infusion necessary.

An announcement of the latest injection of aid could come late Wednesday or Thursday.

Treasury spokesman

Andrew Williams declined to offer details, but said: "Treasury is in discussions with GMAC to ensure its capital needs as determined ... by the stress tests are met."

GMAC spokeswoman Gina Proia on Tuesday night declined comment on reports of the new aid but said the company "has been conducting a strategic review of its business and evaluating options to address the challenges in its mortgage operation."

Proia said GMAC was trying to position itself to improve its financial performance and repay the U.S. government.

Michael Carpenter, who succeeded Alvaro De Molina as the company's CEO in November, has said the company would need no more than $5.6 billion in aid. Lawmakers estimated the company would receive between $2 billion and $5 billion in additional aid.

Despite the government support, GMAC still remains on shaky financial ground. Last month, it reported a quarterly loss of $767 million, though the results were an improvement over a giant loss a year ago. ResCap lost $747 million during the third quarter as homeowners continued to default on their mortgages in large numbers.

GMAC has also been hurt by the rapid decline of the U.S. auto industry after sales crumbled due to the recession and financial woes of the big automakers. Sales of cars and trucks were down 24 percent through November compared with the same part of last year.

Despite the drop in auto sales, GMAC's auto lending business has shown some signs of revival. The auto financing division earned a profit of $395 million during the third quarter. The company's online consumer banking unit, Ally Bank, has also been a bright spot by bringing in billions of dollars in new deposits by offering relatively high interest rates.