An industry group says China's auto sales growth tumbled to 7 percent in January amid an economic slowdown.

The China Association of Automobile Manufacturers said Thursday consumers in the world's biggest auto market bought 1.85 million passenger vehicles, the first time monthly sales surpassed 1.8 million.

Auto sales growth is forecast to decelerate sharply from last year's 15.7 percent expansion to about 8 to 10 percent.