The value of the inventories of 44 listed auto dealers in China has reached 29.7 billion yuan ($4.70 billion) in the first half of the year, indicating a slowdown of the country's car market, according to the China Automobile Dealers Association.

The stocks of domestic brands are significantly higher than those of imported and joint-venture brands.

In the first half, the inventory of Wuhu Yaxia Automobile Corp, a leading regional car dealer, increased 60.84 percent compared to the same period last year.

"The sales competition between car dealers and manufacturers is very intense," said Cui Dongshu, deputy secretary-general of the China Passenger Car Association.

"Overstocking at dealers may be a big threat to automakers," Cui said.

With purchasing power in China increasing, car dealers had high expectations for imported car sales.