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Apple has invested $1 billion in China's ride-hailing service Didi Chuxing, a move that deepens the company's ties to the world's largest market.

The Cupertino technology giant's investment gives Apple, which has been hiring auto industry veterans for its own unannounced vehicle project, a stake in Uber's principal rival in China.

Apple Chief Executive Tim Cook told Reuters that the company hopes to better understand the Chinese market through the investment, and potentially explore future collaborations.

Didi President Jean Liu said the deal came together at "lightning speed." She recalled a meeting with Cook on April 20 in Cupertino, in which the executives shared a moment of levity.

"Our company's legal name is called 'little orange,'" Liu said in a briefing with journalists. "We figured the company named after a fruit can always achieve something big."

Liu talked broadly about collaborating with its new investor on products, technology and marketing, though she declined to say whether Apple had discussed its long-rumored autonomous car project.

"This is still at an early stage," Liu said. "So we couldn't share more."

Didi, like its American counterpart Uber, has an interest in self-driving vehicles and is building a network to support human drivers and autonomous cars, Liu said.

The only automotive project Cook has talked about publicly is Apple's CarPlay, which connects a smartphone to a vehicle's entertainment system.

Asked whether Didi could help improve Apple's relationship with the Chinese government, Liu punted and referred reporters to Apple.

China is Apple's second-largest market. But fears of the Chinese government cracking down on Apple — forcing the company to shut down its iTunes Movies and iBook services in the market — prompted investor Carl Icahn to sell his shares in the company.

Apple joins Chinese tech giants Tencent and Alibaba as strategic investors in the fast-growing taxi- and car-hailing service.

Didi, previously known as Didi Kuaidi, is looking to fend off competition from American rival Uber. It also has global expansion ambitions of its own, partnering with Lyft in the U.S. and Grab (formerly GrabTaxi) in Southeast Asia.

Liu said the company is also focused on growing its domestic market where, despite a presence in 400 cities, it commands a mere 1 percent share of the entire Chinese market.

Liu and Anthony Tan, CEO and founder of Grab, will both be speaking at the Code conference at the end of May.