Auto sales are expected to end the year strongly, increasing 14 percent in December for the second highest monthly selling rate as consumers shake off fears about economic uncertainty, consultants J.D. Power & Associates and LMC Automotive said on Thursday.

LMC also boosted its 2012 forecast for total new light-vehicle sales in the United States to 14.5 million vehicles from 14.4 million. That would be an increase of 13.3 percent from 2011.

The auto industry has been steadily recovering since 2009, when U.S. sales hit a 28-year low of 10.4 million vehicles.

For December, they see sales rising 14 percent to almost 1.36 million vehicles and an annual selling rate in the month of 15.3 million vehicles, which would trail only November's 15.54 million rate as the strongest of the year.

"The U.S. light-vehicle sales market continues to be a bright spot in the tremulous global environment," LMC Senior Vice President Jeff Schuster said in a statement.

"The only major roadblock ahead for the U.S. market is the fiscal cliff," he added, referring to talks in Washington to avoid automatic federal spending cuts and tax increases that could tip the economy back into recession. "Assuming that hurdle is cleared, 2013 is one step closer to a stable and sustainable growth rate for autos, with volume above the 15 million unit mark."

In addition, they forecast that luxury vehicle sales were on pace to account for 16 percent of all retail vehicles sold in December. That would be an increase from 15.3 percent in November, and the highest rate for the year as well as the strongest rate since December 2009, when it reached 16.2 percent.

"Luxury sales always do well this time of the year, but December is turning out to be a great month," J.D. Power Senior Vice President John Humphrey said. "New and redesigned vehicle introductions, along with enhanced incentive activity, have been key drivers of the recovery in the luxury market."