UPDATE 1-China tops up rubber reserve by 50,000 T -sources

(Adds details, quotes)

BEIJING, Oct 29 (Reuters) - China has bought an additional 50,000 tonnes of rubber from the domestic market to boost reserves, industry sources said, bringing the total amount of state purchases to about 105,000 tonnes this year.

The purchases late last month included rubber from the country's main growing provinces but details only emerged this week. China, the world's largest rubber consumer, had initially planned to buy 65,000 tonnes of rubber to stabilise rubber prices and help farmers.

"Of the total purchase, 55,000 tonnes came from Hainan province and the other 50,000 tonnes from Yunnan," said a dealer from a state-run firm involved with the purchase.

"The purchases were concluded at the end of September," said the dealer, without giving other details.

China imports about half of what it consumes and expects demand for rubber to rise 8.5 percent to 6.4 million tonnes in 2010 because of strong growth in the country's auto sector, according to the China Rubber Industry Association. [ID:nSP449300]

China has been a rare bright spot in the struggling global auto industry as government incentives spurred an increase in demand. China overtook the United States as the world's biggest automaker in January.

General Motors Co [GM.UL] expects China's car market to grow over 10 percent next year even without government incentives and maintain its position as the world's top car market for a long time. [ID:nSEO350079]

China's industry-wide car sales in 2010 are expected to grow to over 13 million vehicles from an expected 12.5 million this year, GM International Operations President Nick Reilly told reporters late on Wednesday. (Reporting by Beijing newsroom and Chen Aizhu; Editing by Lewa Pardomuan and Clarence Fernandez)