HONG KONG » General Motors Co. and its local Chinese partners have launched a second plant to make cars for its local discount brand Baojun, ratcheting up the battle for customers at the fast-growing lower end of the world’s biggest auto market.

The SAIC-GM-Wuling joint venture opened the factory Sunday in southwestern Guangxi province. GM and its partners have invested $1.3 billion in the facility, which will be capable of turning out up to 400,000 vehicles a year.

The first car to roll off the plant’s production line was a Baojun 630 midsize sedan, one of two cars sold under the only-in-China badge. The 630 sells for about 63,000 yuan — $10,100 — while the Le Chi mini­car goes for about 40,000 yuan — $6,400.

In September, Nissan unveiled the second model from its new low-priced Chinese brand Venucia, a compact hatchback that will sell for as little as 67,800 yuan — $10,760. Honda has also launched a budget brand, Li Nian.