Sales revenue of Beijing's auto market in 2011 is estimated to drop by 60 billion yuan ($9.1 billion), as the city puts cap on the number of cars bought each month, said a commerce official.

Car sales revenue in Beijing will drop to 100 billion yuan ($15.1 billion) in 2011 from last year's 160 billion yuan ($24.2 billion), said a Xinhua report quoting Wang Shuxia, chief of marketing, the Beijing municipal commission of commerce.

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

Last year, Beijing witnessed sales of more than 800,000 new cars, adding to the traffic jams woes in the city.

Wang said car sales in Beijing is estimated to reach 580,000 units, as some cars will be sold to buyers outside the city while others will be purchased by buyers who are replacing older cars.

However, car owners who are looking to replace their old vehicles can directly obtain the car license plates without participating in the city’s lottery scheme that allots 20,000 new plates each month, the report said.