DETROIT - U.S. auto sales in December are on pace to rise by 14 percent from a year earlier to hit an annualized rate of 12.4 million vehicles, industry tracking firm J.D. Power and Associates said.

The market research firm said retail sales were "significantly beating expectations" in December, while sales of cars to fleet operators such as car rental agencies were lower as a share of total volume than they have been to date in 2010, Reuters reported.

That trend would be an encouraging sign for an industry that has seen a slower-than-expected rebound in U.S. sales this year.

J.D. Power tracks auto sales based on transaction data from about 8,900 auto dealerships across the United States, so its forecasts are closely watched.

"The continuation of the strong performance in the retail market through December may be the confirmation that the industry has been looking for that the recovery has been re-engaged," Jeff Schuster, executive director of global forecasting at J.D. Power and Associates, said in a statement today.

"The likelihood of an extension of the tax cuts, in addition to a strong close in 2010, bodes well for the automotive market in 2011," Schuster added.

For most of the year, major automakers have relied heavily on demand from fleet buyers, while U.S. consumers had held back due to the uncertainty around the market for jobs and housing, analysts have said.

J.D. Power said it expected overall auto sales to rise to about 1.13 million vehicles in December, up 14 percent from a year earlier.

The retail share of overall sales is expected to be up 19 percent.

J.D. Power also raised its full-year sales forecast slightly to 11.6 million vehicles from 11.5 million to reflect the stronger sales expected for December.