HONG KONG/BEIJING (Reuters) - Taiwan's Foxconn has invested $119.9 million in Chinese ride-hailing firm Didi Chuxing via one of its subsidiaries, the world's largest electronics manufacturer said on Thursday, in a deal that could value the start-up at about $33.7 billion.

With the addition of Foxconn, Didi's roster of investors is increasingly a who's who of global tech giants, including the likes of Apple Inc <AAPL.O>, Uber Technologies Inc [UBER.UL] and Chinese firms Tencent Holdings Ltd <0700.HK>, Alibaba Group Ltd <BABA.N> and Baidu Inc <BIDU.O>.

The deal was made public in a stock exchange filing by Hon Hai Precision Industry Co Ltd <2317.TW>, the trading name of Foxconn. In the statement, Foxconn said its subsidiary Foxteq Holdings Inc would own 0.355 percent of Didi, one of China's highest-valued start-ups.

The transaction gives Didi a valuation of $33.7 billion, according to Reuters' calculations.

The two companies now "are exploring possibilities but there are no concrete plans yet," a Didi spokeswoman said in an email.

In a coup for the Beijing-based firm, it last month agreed to buy ride-hailing rival Uber's China unit after a bruising two-year battle, a deal that in return gave the U.S. company a one-fifth stake in Didi.

The merged entity was worth around $35 billion, combining Didi's most recent $28 billion valuation and Uber China's $7 billion worth, a source familiar with the matter said at the time.

Foxconn has previously invested in the auto industry with a stake in Future Mobility. That company, also backed by Tencent, is one of an expanding field of China-backed ventures that aim to take on Tesla Motors Inc <TSLA.O> as green energy car sales boom in China.

Foxconn also has close ties to Apple, as the U.S. company's main assembler of iPhones. Apple in May invested $1 billion in Didi, and the U.S. titan is expected to enter the automotive business.

At the same time, Silicon Valley has been buzzing about Apple's plan to build an electric car. In May, Reuters reported the company appeared to be laying the groundwork for the infrastructure and related software crucial to powering such a product.

(This version of the story changes the stake size in paragraph 4 to 0.355 pct from 0.36 pct after company issues corrected statement. Changes valuation estimate in paragraphs 1 and 4 to $33.7 bln from $33.3 bln as a result.)

(Reporting by Twinnie Siu in Hong Kong and Paul Carsten in Beijing; Editing by Mark Potter)