U.S. lithium-ion battery maker A123 Systems Inc said it is forming a joint venture China's top carmaker SAIC Motor Corp to develop, make and sell battery systems for electric vehicles.

The venture would make complete vehicle traction battery systems for hybrid electric and pure electric passenger vehicles and heavy-duty truck and bus applications in the world's largest and fastest growing auto market, A123 Systems said in a statement on Thursday.

Shanghai Advanced Traction Battery Systems Co would be owned 51 percent by SAIC and 49 percent by A123 Systems, the statement said without disclosing the investment amount.

It said the venture had been awarded a contract to supply battery systems for SAIC's plug-in hybrid vehicle programme.

It added that SAIC had plans for a hybrid Roewe 750 sedan and a plug-in hybrid version of the Roewe 550, which could cut fuel consumption by 20 percent and 50 percent respectively. Both models would utilize A123 battery cells.

The Chinese carmaker planned to launch electric vehicles for sale in 2012, it added.