Sales revenue of Beijing's auto market in 2011 might shrink by 60 billion yuan (about 9.1 billion U.S. dollars) due to the city limiting the number of cars purchased each month, a commerce official said Saturday.

Car sales revenue will drop to 100 billion yuan in 2011 from last year's 160 billion yuan, Wang Shuxia, chief for marketing section with the Beijing Municipal Commission of Commerce, told a working meeting of the commission.

A control on car purchases introduced this year limits new car license plates to 240,000 in 2011, said Wang.

In 2010, more than 800,000 new cars drove onto Beijing's roads, worsening the chronic gridlock in this Chinese national capital of nearly 5 million automobiles.

Wang estimated that Beijing's car sales this year will hit 580,000 units, as some cars will be sold to buyers outside of Beijing while others will be purchased by buyers who are replacing older cars.

Car owners who replace their old vehicles can obtain car license plates directly without taking part in the lottery that allots 20,000 new plates each month.