A potential $1 billion investment in Lyft Inc. would mark a new direction in Google's ride sharing strategy. 

Alphabet Inc.'s   (GOOGL)  search unit is reportedly exploring an investment in Lyft, Bloomberg reports. Google already has a stake in Uber, but is also suing Lyft's ride-sharing rival in an intellectual property dispute. 

Google would join an already plentiful group of Lyft backers that includes Chinese tech powers such as e-commerce giant Alibaba (BABA) , ride-sharing group Didi Chuxing, and Internet group Tencent; automakers General Motors (GM) and Jaguar Land Rover; and prominent investment firms including KKR (KKR) and VC firm Andreessen Horowitz. 

Among ride-sharing startups, Lyft has raised the fourth-largest amount of capital, according to CB Insights, with about $2.5 billion raised at a valuation of $6.9 billion. Lyft's most recent financing, a $600 million round that closed in April, was led by KKR. 

Ahead of Lyft are Uber, which has raised $15.1 billion with a current valuation of $68 billion; Didi Chuxing, which has raised $14.1 billion; and Singaporean ride sharing company Grab, which has raised $3.44 billion.

Google has a complicated relationship with Uber, to say the least.

The search giant invested more than $250 million in Uber through its GI venture capital arm in 2013. But Google's self-driving car unit Waymo sued Uber earlier this year, alleging that a former Google engineer at Uber's self-driving vehicle outfit Otto stole Waymo's intellectual property. This week, a California court declined Uber's request to move the dispute to arbitration.

It's been a turbulent year for Uber. Following multiple claims of sexual harassment and misconduct at the company, former Expedia (EXPE) CEO Dara Khosrowshahi recently took over from ousted founder Travis Kalanick. The FBI is also reportedly investigating whether Uber created software, dubbed Hell, to illegally track the location and rates charged by Lyft drivers. Uber did not immediately respond to a query about the probe.

Uber may get support from Softbank Corp., however. Softbank founder Masayoshi Son has acknowledged that he is considering an investment in Uber, which could reportedly total $10 billion, with some of the money potentially going to buy out existing Uber investors. Google would not say if it is selling its stake in Uber.

The potential investment from Google comes as Lyft launches a self-driving car pilot program in the San Francisco Bay area with autonomous vehicle software developer Drive.AI.

Google and Lyft declined to comment for this story.

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Editors' pick: Originally published Sept. 15.