General Motors Co opened a new, large vehicle test track in China Saturday as part of its push to retain its leading market share in the world's largest auto market.

The No. 1 US automaker and its joint venture partners, including SAIC Motor, invested about $252.5 million to build what GM China President Kevin Wale called the country's largest proving ground.

The 1,400-acre (560-hectare) facility was opened in Guangde County, East China's Anhui Province, and will employ about 100 people as part of GM's drive to develop vehicles faster in a market where it had a leading 14 percent share last year.

GM previously used tracks owned by other companies or the government to test vehicles, or shipped cars to other countries, including South Korea or the US, Wale said.