DETROIT — Sales of new vehicles in the United States slowed in September compared with last year, mainly because the Labor Day selling weekend fell in August.
Overall auto sales dropped 4 percent from a year ago to just over 1.1 million. The drop ended a 27-month streak of gains for the industry.
Sales for General Motors Co. fell for the first time since July, 2012, sliding 11 percent in September, to 187,195 vehicles. Sales of its Chevrolet brand tumbled 14.7 percent, while GMC brand sales dropped 9.7 percent. GM, the nation’s largest automaker, was helped by a 9.9 percent gain for Cadillac and 6.5 percent for Buick.
“September had only 23 selling days,” said Kurt McNeil, GM’s vice president for United States sales operations. “All of this goes a long way in explaining the month-to-month decline” in the annual rate of industrywide sales.
While sales fell for most automakers, Ford Motor Co. and Chrysler Group LLC bucked the industry trend.
Ford said its sales rose 5.8 percent for its best September performance since 2006. It sold 185,146 vehicles, or 2,049 fewer than General Motors, to narrow a gap that hasn’t been closed since March, 2011.
The Chrysler Group reported sales rose 0.7 percent, extending a streak of consecutive year-over-year sales gains to 42 months.
Chrysler’s Ram trucks division rose 8.2 percent, compared with 1.6 percent for the Chrysler brand and 2.6 percent for Dodge. Jeep sales fell 4.5 percent.
Chrysler sold 11,984 Wranglers, which are all made in Toledo. That was down about 1 percent from the 12,097 sold in September, 2012. So far this year, Wrangler sales are up 11 percent to 119,941.
Fiat sales were down 24.4 percent, falling for the first time in 18 months.
At Honda Motor Co., sales dropped 10 percent as two of its most popular models, the Accord midsize car and the CR-V small crossover SUV, posted declines.
Toyota Motor Corp. said its sales fell 4.3 percent in September. Nissan Motor Co.’s sales dropped 5.5 percent, with its Nissan brand falling 5.6 percent and its Infiniti brand dropping 4.3 percent.
Volkswagen of America Inc. fell 7.5 percent, with sales of its VW brand falling 12.2 percent. Analysts said VW continued to struggle because of an aging portfolio and increased competition among small cars, despite the automaker’s doubling of its incentive spending over September, 2012.
The double-digit gains automakers reported over the summer moderated in September because two of the industry’s busiest sales days — the Saturday and Sunday before Labor Day — took place in August, contributing to that month’s robust figures.
“September’s performance can be attributed to the timing and strength of the Labor Day weekend,” Erich Merkle, Ford’s U.S. sales analyst, said in a conference call.
“You’re going to see a lot of strange stuff in the year-over-year comps,” Mr. Merkle added.
GM and Ford said they did not expect Tuesday’s government shutdown to affect operations over the long term.
Jim Lentz, Toyota’s North American CEO, said the shutdown will only affect sales if it causes credit markets to tighten.