SHANGHAI, China - General Motors Corp. and its joint venture partners said Tuesday their combined sales in China jumped 25 percent in the first quarter, a boon for the U.S. automaker struggling to revive sales at home.

GM is the No. 1 seller of autos in China, the world's second-biggest and fastest-growing vehicle market.

The company said its sales in China totaled 291,588 vehicles in the first three months of the year. In March alone, it moved 100,538 units, just the second time single-month sales have topped 100,000, it said in a release.

The first-quarter performance nudged GM's share of the Chinese vehicle market up 0.5 percent point over the same period last year to an estimated 13.9 percent, it said.

In 2005, GM overtook Germany's Volkswagen AG as China's biggest automaker. In 2006, GM's sales in the country rose 32 percent to 876,747 vehicles.

"Coming off a record year in 2006, China's vehicle market has remained remarkably strong thus far in 2007," Kevin Wale, president of GM China, said in the release.

Wale said growth was led by demand for passenger cars.

Shanghai General Motors Corp., one of the company's seven joint ventures in China, chalked up sales growth at 26.5 percent with 113,768 vehicles.

Buick continued to be Shanghai GM's top brand in China, with sales rising 25.3 percent to 82,195 vehicles in the first-quarter. The Buick Excelle was the brand's best selling model, although the news release gave no exact sales numbers.

Chevrolet, the company's second mainstream brand in China, saw a 19 percent jump in sales to 41,144 vehicles, with 4,428 Sparks and 3,629 Epicas sold in March alone. Sales of the Cadillac marque soared 62.2 percent in the first quarter to 1,797 units.

Another joint venture, minivan and subcompact maker SAIC-GM-Wuling, accounted for sales of 177,077, up 24 percent. The remaining 743 vehicles sold were imports.

GM has leaned heavily on China to balance out sluggish sales and crippling legacy costs in the U.S. and elsewhere, and on Monday said it would use this month's Shanghai Auto Show to debut a pair of concept cars in its Chevrolet and Buick lines.

China surpassed Japan last year to become the world's No. 2 vehicle market after the United States based on strong truck and bus sales, but is still in third place for passenger cars.