GUANGZHOU -- China's Guangzhou Automobile Group is bringing its eco-friendly car business into full swing, with plans to build a dedicated factory here and roll out new electric and plug-in hybrid vehicle models.

The automaker, also known as GAC, will spend 4.7 billion yuan ($681 million) for its first plant focused exclusively on green vehicle production. Construction kicked off recently and the facility is scheduled for completion at the end of 2018. Its initial 200,000-unit annual output capacity is expected to eventually rise to 400,000. The factory will produce vehicles such as electric versions of its Trumpchi brand cars.

The company plans to begin selling four environmentally friendly car models this year, with the plug-in hybrid edition of its GA3S sedan set to hit stores in May, followed in June by the electric GE3 and the plug-in hybrid version of its flagship GS4.

Ahead of its planned market entry into the U.S. at the end of 2019, the carmaker will open a Silicon Valley research hub in early May, where it will explore ways to limit gas emissions and boost fuel economy.

Through 2016, Guangzhou Automobile had focused on selling compact sport utility vehicles, which were eligible for the Chinese government's small-vehicle tax break. But with that program set to end this year, and stricter fuel efficiency standards to take effect in 2018, the company is moving to bolster its green car lineup.