GM sold 203,367 vehicles in China last month, the automaker said in a statement. That compares with sales of 213,112 units last April. The decline follows delivery growth of 1.2 percent in March and a 6 percent increase in February.

Automakers including GM, Toyota Motor Corp., and Honda Motor Co. have seen car buying slow this year after China reinstated a 10 percent tax rate on small-car sales and phased out subsidies for vehicle trade-ins in rural areas. GM, which makes Buick-branded cars and Wuling minivans with Chinese partner SAIC Motor Corp., aims to double sales in the world's largest auto market to 5 million units by 2015, it said last month.

The automaker boosted China sales 29 percent to 2.35 million vehicles last year, helped by state incentives and economic growth.

Sales by SAIC-GM-Wuling Automotive Co., the minivan venture that makes the Wuling Sunshine, China's best-selling vehicle, totaled 100,262 vehicles in April.

GM Chief Executive Officer Dan Akerson is counting on emerging markets including China to help drive growth after an initial public offering of more than $20 billion in November. The carmaker plans to boost investment in China and introduce 60 new and upgraded models over the next five years, it said during the Shanghai Auto show last month. The company estimates it has a 14.7 percent market share in China.

Last year, China's overall auto sales surged 32 percent to a record 18.06 million, helping make the nation the world's largest vehicle market for the second year running.

Passenger-car sales in 2011 may grow slower than an earlier forecast of 10 percent to 15 percent, the China Association of Automobile Manufacturers said this month.