China's Ganfeng Lithium Co Ltd and its unit GFL International Co Ltd have signed a contract to supply battery-grade lithium products to U.S. electric vehicle (EV) maker Tesla Inc.

Ganfeng, the world's top lithium company by market capitalisation, has already supplied battery-grade lithium to EV producers including Tesla.

The new contract will allow the company and its unit to provide products to Tesla for three years starting from 2022, Ganfeng said on Monday in a filing to the Shenzhen Stock Exchange.

The sales amount and value of the contract are still pending Tesla's purchase orders, according to the filing.

Ganfeng has posted stellar earnings this year, with its third-quarter and nine-month net profits up 507% and 648% on an annual basis, respectively, thanks to rising lithium prices and robust demand.

The Jiangxi-based firm also announced an 8.4 billion yuan ($1.31 billion) investment in two battery production projects in August.

Ganfeng's share price, up more than 60% this year, closed at 162.1 yuan on Monday.

($1 = 6.3965 Chinese yuan renminbi)

(Reporting by Min Zhang in Beijing and Meg Shen in Hong KongEditing by Jan Harvey and Mark Potter