BEIJINGSAN FRANCISCO Reuters U.S. autonomous truck startup Plus said on Wednesday it had raised an extra 220 million from investors in an extension of a 200 million funding round in February, as the global auto industry looks to a driverless future.

A source with direct knowledge of the matter also said Plus was in advanced talks with a few special purpose acquisition companies SPAC over a potential merger, adding an announcement was expected within weeks.

SPACs are becoming an increasingly popular way for private companies to seek public listings as a cheaper and less administratively burdensome alternative to an initial public offering IPO.

The latest funding round was led by FountainVest Partners and ClearVue Partners, Plus said in a statement. Other investors included Quanta Computer Inc and Millennium Technology Value Partners, as well as existing investors including Sequoia Capital, SAIC Motor and Full Truck Alliance.

Plus raised 200 million in February from investors such as Guotai Junan International, CPE, and Wanxiang International Investment.

Plus did not disclose its valuation after the fundraising.

The Cupertinobased startup, which was founded in 2016, has a joint venture with Chinas stateowned automaker FAW to develop and build autonomous trucks. It is testing trucks in the United States, China and Europe.

With the funding it will accelerate its production and deliveries of autonomous trucks and improve research capabilities.

Automakers and…