July 7 (Bloomberg) -- General Motors Corp., the biggest overseas automaker in China, posted slower sales growth in the first half than a year earlier on increasing competition from Toyota Motor Corp. and Volkswagen AG.

The carmaker boosted sales 13 percent in the period to 590,126 vehicles, it said in an e-mailed statement today. Sales of Chevrolets jumped 35 percent. The automaker raised sales in China 19 percent in the first half of last year.

GM didn't add any new models in the first half, while Toyota won customers with the Yaris compact and Volkswagen debuted the Lavida compact. The Detroit-based automaker plans to begin selling the Chevrolet Aveo 1.2 and the Buick LaCrosse Eco-Hybrid in the second half, as it seeks higher China sales to offset slumping U.S. demand

GM sold 109,131 Chevrolets in China in the first half, led by demand for Lova and Epica sedans, according to the statement. Both models are made by Shanghai General Motors Co., GM's venture with SAIC Motor Corp., China's largest automaker.

Buick sales totaled 146,321, GM said, without providing a percentage increase. Sales at SAIC-GM-Wuling Automobile Co., GM's minivan-making venture, jumped 18 percent to 349,871.

China's car sales climbed 17 percent to 3.02 million vehicles in the first five months, the China Association of Automobile Manufacturers said June 6.

GM's sales in the U.S., the world's biggest auto market, fell 16 percent in the first half, outpacing a 10 percent decline in the overall market.

To contact the reporters on this story: Neil Denslow in Hong Kong at ndenslow@bloomberg.net

Last Updated: July 7, 2008 06:20 EDT