Aug 4 (Reuters) - Mongolia's massive Tavan Tolgoi project began shipping 4,000 tonnes of coal south to its new partner, the Aluminum Corp of China Ltd (Chalco) on Thursday following a ceremony at the mine site.

The mine's state-owned operator, Erdenes Tavan Tolgoi, agreed last week to sell $250 million worth of coal to the Chinese company from its east Tsankhi block, a move designed to fund the deposit's overseas listing scheduled for next year.

A total of 40 trucks each loaded with 100 tonnes of Tavan Tolgoi coking coal has already set off south to China, Erdenes confirmed.

The mine, which could contain as much as 7.5 billion tonnes of high-quality coking coal, is expected to help transform Mongolia's tiny economy over the next decade, and it has attracted the attention of scores of overseas investment banks and mining firms.

But it remains unclear when large-scale development of the property will begin, with the results of a bidding process for the western section of the mine still in dispute.

Tavan Tolgoi was first discovered in the 1930s, but it did not begin exporting coal to China until 2007, with its remote location in South Gobi, Mongolia's biggest and least populated province, making development and transportation difficult. (Reporting by Khaliun Bayartsogt; Writing by David Stanway; Editing by Ken Wills)