NEW YORK — Ally Financial seized on a market buoyed by new loan originations to claim the title of largest auto finance company in the United States in 2010, according to the new Auto Finance Big Wheels annual ranking of car lenders and lessors.

Ally Financial, the bank-holding company that used to be known as GMAC, amassed an auto finance portfolio of $74 billion last year, $10 billion more than Toyota Financial Services, which came in second in the Auto Finance Big Wheels ranking.

“Ally entered 2010 with a new brand, the overhang of its federal government bailout, and performance uncertainty swirling around its largest patron, General Motors, and rose above all that adversity to exit 2010 as the No. 1 lender in the land,” said Marcie Belles, editor of Auto Finance Big Wheels. “It's a testament to Ally's comprehensive strategy to garner share in all segments of the industry.”

The top 10 auto finance companies in the U.S. last year were:

1. Ally Financial
2. Toyota Financial Services
3. Chase Auto Finance
4. Ford Motor Credit Co.
5. Wells Fargo Dealer Services
6. Bank of America Dealer Financial Services
7. American Honda Finance Corp.
8. BMW Financial Services
9. Nissan Motor Acceptance Corp.
10. Santander Consumer USA

Auto Finance Big Wheels ranks the top 100 car finance companies in the nation by pouring through public documents, receiving data directly from lenders, and by applying a propriety formula for calculating outstandings and originations based on a variety of criteria. The 2011 report is the 12th annual Big Wheels published by Auto Finance Advisors, a consultancy dedicated to providing research and advisory services to the automotive lending and leasing market.

After the credit crisis sent the auto finance sector into a tailspin, the tide was turned in 2010 by a 31 percent increase in loan originations, compared with a year earlier. Toyota originated the most auto loans and leases last year.

“Last year saw the auto finance market resuscitate, and we forecast the industry to truly get its mojo back in 2012, particularly since car sales have taken off so far this year,” said Belles, who is also a principal at Auto Finance Advisors. “The market has a bright future.”