Low interest rates spurred an uptick in car loans in the Washington area, where the top 25 auto lenders grew their portfolios an aggregate 3 percent to $31.5 billion in the last three months of 2011, according to SNL Financial.

Regulators only began requiring banks to disclose auto loans in the first quarter of last year, which is why there is no data available for an annual comparison.

Capital One Financial Corp.’s portfolio accounted for nearly 70 percent of the total auto loans within the reviewed cohort. The McLean-based institution registered a 6.6 percent increase over the third quarter 2011 to $21.7 billion in the fourth quarter.

Credit unions dominated the ranks, though they posted mixed quarterly results. Vienna-based Navy Federal Credit Union, for instance, reported a 0.5 percent decline in the three months ending December, but registered a 4 percent increase to roughly $5.6 billion for the year.

One of the largest spikes in auto loans occurred at NASA Federal Credit Union in Upper Marlboro, which recorded a 32.7 percent rise for the quarter and 25 percent jump for the year. Meanwhile, Fairfax-based Apple Federal Credit Union grew its book of auto loans 18.5 percent in the fourth quarter and 26 percent for the year.

At Virginia Heritage Bank in Vienna, year-over-year auto lending was flat, though within the last three months of 2011 auto loans climbed 12.8 percent to $65.8 million. Chief operating officer Charles C. Brockett explained that the supply chain disruption caused by the earthquake in Japan and floods in Thailand tempered loan growth.

“We do a fair amount of import financing, so those natural disasters resulted in a slower pace of lending than we anticipated,” he said. But,“the momentum from the fourth quarter was strong, and we’re seeing it continue into 2012.”

Consumer appetite for cars was evident in the February retail sales figures from the Commerce Department, which tracked a 1.7 percent increase over the prior year to $70.5 billion in sales. Analysts anticipate continued purchases through the year, if interest rates on vehicle loans remain low.

Auto interest rates last year fell to the lowest levels since 2008, according to Experian Automotive. The average interest rate on a loan for a new vehicle slid to 4.52 percent in the fourth quarter of 2011, down from 4.84 percent a year earlier. The rate dropped from 8.71 percent in the fourth quarter of 2010 to 8.68 percent in 2011 for used cars.

Consumers are not only taking advantage of these rates to purchase vehicles, but to also refinance existing ones. Applications to refinance car loans in the Washington area climbed 6.5 percent from January to March 15, 2012, compared to a year ago, according to LendingTree.com.

Ken Orgeron, vice president of lending at Apple FCU, said he began noticing more members inquiring about auto refinancing last year. The credit union closed out 2011 with a 31.3 percent rise in refinanced auto loans.