Full-year sales for 2014 are expected to finish around 16.5 million vehicles, matching the number in 2006. Rising demand has allowed automakers to boost prices for their vehicles, however.
Kelley Blue Book, an industry source for vehicle valuations, said Monday the average transaction price for a new vehicle sold in the U.S. market in December was a record $34,367, up 2.5 percent from a year ago.
Pricing fell 1.2 percent for hybrid and other alternative fuel cars as gasoline prices continued to fall, KBB said.
GM's December transaction prices grew 4 percent from a year earlier to $38,816, KBB said.
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Fiat Chrysler's U.S. sales jumped 20 percent in December on strong Jeep SUV and pickup truck sales, but still missed analysts' expectations. FCA's sales of 193,261 for the month were the highest since 2006 for the company once known as Chrysler.
Nissan Motor's December U.S. sales narrowly beat expectations, while Honda Motor's sales fell short.
Nissan on Monday said its U.S. sales grew 7 percent to 117,318 vehicles, and that 2014 sales of 1.39 million vehicles were a company record.
However, while Honda's U.S. sales rose 1.5 percent to 137,281 vehicles, the figure was well short of analysts' expectations of about 143,000 vehicles in December. For the year, Honda sales were up 1 percent at 1.54 million vehicles.