China's SAIC Motor, the largest domestic auto maker, said Tuesday that unaudited net profit rose more than 40 percent last year, despite an overall slowdown in the world's biggest car market.

SAIC gave no net profit figure for 2011 in a statement to the Shanghai stock exchange, but said net profit was 13.73 billion yuan ($2.18 billion) in 2010.

The Shanghai-based company, which has joint ventures with US auto giant General Motors and Germany's Volkswagen, sold more than 4.0 million vehicles in 2011, up 12 percent from 2010, it said.

China's total auto sales rose just 2.5 percent to 18.51 million units last year, the China Association of Automobile Manufacturers has said, compared with an increase of more than 32 percent in 2010.

Growth in auto sales slowed in 2011 after Beijing rolled back purchasing incentives and some cities imposed restrictions on car numbers.

GM said earlier this month that its joint venture with SAIC, Shanghai GM, was Chinas passenger car sales leader in 2011. It sold more than 1.2 million vehicles domestically, up more than 16 percent from 2010.

China has moved to protect its domestic auto industry in recent months, slapping import tariffs on some US passenger cars and sports utility vehicles.

On Monday, Beijing formally withdrew support for foreign investment in auto manufacturing under new rules, as it seeks to encourage domestic players.

The guidelines -- released by state planner the National Development and Reform Commission and the Commerce Ministry on December 30 -- signal an end to incentives for foreigners and discourage fresh projects in China.

Foreign car makers have outperformed their domestic rivals as Chinese consumers increasingly favour high-quality vehicles with better safety standards, analysts say.