The slowdown is a setback for global automakers that look to China to drive revenue and are spending heavily to develop models for local tastes.
Sales of SUVs, normally the industry’s brightest spot, shrank 10.1 percent to 872,800, according to CAAM.
Sales of electric and gasoline-electric hybrid autos that Beijing is spending heavily to promote grew strongly.
September purchases of electrics rose 66.2 percent over a year earlier to 541,000. Hybrid sales gained 146.9 percent to 181,000.
Automakers are rolling out dozens of electrics but gasoline-powered models supply their profits.
— General Motors Co. said sales in the three months ending in September declined 14.9 percent from a year ago to 835,934. For the first nine months of the year, sales declined 2.5 percent to 2.7 million.
— Volkswagen AG sales in China and Hong Kong fell 5.7 percent to 383,500. Year-to-date sales rose 5 percent to 3 million.
— Nissan Motor Co. sales shrank 0.8 percent to 141,195. For the first nine months, sales rose 7.4 percent to 1.1 million.
— BMW AG sales, including MINI vehicles, gained 13.2 percent to 59,616. Year-to-date sales were up 5.3 percent at 459,629.
China Association of Automobile Manufacturers: www.caam.org.cn