Expect a 15 percent spike in new vehicle sales in December, powered by a retail surge, according to projections released today by industry forecaster J.D. Power and Associates.

“The market is continuing to improve, with the relative strength of December sales supporting a year-end rally,” Gary Dilts, senior vice president of global automotive operations at J.D. Power, said in a statement.

December would be just the third month of 2009 with a sales increase. The others, in August and in November, had tiny gains. The August advance stemmed from the U.S. cash-for-clunkers incentive program. November and December benefited from comparisons to a market that collapsed at the end of 2008.

Total December sales are projected at 1.03 million vehicles, up from 895,152 a year earlier. J.D. Power expects December retail sales to jump 20 percent to 839,600. Fleet sales should drop by 2.5 percent, or 5,000 vehicles.

The seasonally adjusted annual sales rate for December is tracking at 11.2 million vehicles, Dilts said.

That is higher than November's rate of 10.5 million and it would be third highest of the year, according to the Automotive News Data Center. Total light-vehicle sales in November were 747,086.

J.D. Power based its forecast on sales activity during the first 17 days of the month.

During the first 11 months of the year, U.S. light vehicle sales plunged 24 percent to 9.4 million. Subaru, Hyundai and Kia are the only brands to advance this year.