UPDATED: 1/3/14 4:54 pm ET
DETROIT -- General Motors' sales slipped 6 percent in December, as all four of its brands posted weaker results while GM lost market share in the key pickup segment.
For the year, GM sales rose 7 percent, short of the industry's 8 percent growth. As a result, GM's share of the U.S. light-vehicle market edged down to 17.88 percent in 2013 from 17.91 percent in 2012.
GM CEO Dan Akerson said a year ago that he expected the company to gain "modest" market share in 2013.
Through November, GM's U.S. market share stood at 18 percent, up from 17.9 percent during the same period in 2012.
GM said its retail sales for 2013 rose 11 percent, outpacing the industry's retail growth.
Kurt McNeil, GM's vice president of U.S. sales operations, attributed the sales decline partly to "payback" from GM's big Black Friday sales promotion in November, which might have pulled ahead some sales that would have happened in December. Bad weather and competitor incentives also curbed sales, he said.
Chevy sales drop most
Chevrolet sales slid 8 percent, to 153,493 units, the steepest decline among GM's four brands. For the year, Chevy's sales rose 5 percent, to 1.95 million units.
Chevy, which accounted for two-thirds of company sales in December, was hurt by a 16 percent decline in sales of the redesigned 2014 Silverado pickup. Sales of the GMC Sierra pickup fell 5 percent. The trucks were launched in June, their first redesign in nearly seven years.
Meanwhile, Ford F-series pickup sales rose 8 percent last month while Ram's pickup sales increased 11 percent.
Strong incentives offered by rivals slowed GM's pickup sales, McNeil said. GM's incentive spending on full-sized pickups dropped by about $1,000 per pickup from a year earlier, while incentives offered on its "primary competitor" -- a reference to Ford's F-series -- rose by about $250, he said.
McNeil added that most of Ford's pickup sales in December were 2013 models, which Ford was selling "pretty aggressively," while 95 percent of GM's sales were 2014s.
"We think we stayed pretty darned disciplined," McNeil told analysts and reporters during a conference call.
He said that GM still has too many pricier crew cab trucks and not enough double and regular cabs, which appeal to buyers with more modest budgets.
Spending on spiffs rises
Overall, GM boosted incentive spending 4 percent vs. December of 2012, in line with the industry, according to research firm TrueCar. Ford's 22 percent incentive increase was the highest among eight major automakers, TrueCar said.
GM's small car sales also lagged, with Chevrolet Cruze compact sales down 15 percent, Chevrolet Sonic subcompact sales off 26 percent, Chevrolet Spark minicar sales down 23 percent and Buick Verano compact sales down 39 percent.
Buick sales fell 7 percent in December, finishing the year with 205,509 unit sales, a 14 percent increase from 2012. GMC sales declined 2 percent in December and rose 9 percent for the year, to 450,901 units.
Cadillac sales slipped 1 percent in December, the brand's first drop in 14 months. Its sales rose 22 percent for the year, to 182,543 units. That was short of Cadillac's goal of at least 30 percent sales growth.
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