As Uber has its hands full with scandals and a legal battle with Google's self-driving car unit, its rivals aren't sitting still.
Chinese ridesharing giant, Didi Chuxing, is raising between $5 and $6 billion in a funding round that would value the company at around $50 billion, sources tell CNBC. Softbank, Silver Lake and China Merchant Bank are involved.
The latest mega-round would make Didi one of the largest VC-backed start-ups alongside Uber, which has been valued at as much as $66 billion but is now reportedly valued around $50 billion, and Alibaba payments affiliate Ant Financial, reportedly valued around $60 billion.
Earlier this month, Uber's US rival, Lyft, raised a new $500 million round of funding, boosting its valuation to about $7.5 billion, postmoney.
Uber and Didi have a complicated relationship. Once fierce competitors in the Chinese market, Didi bought out Uber's operations in 2016 and gave Uber a 20% stake in the company, along with a $1 billion investment. Didi founder and chairman, Cheng Wei, holds a non-voting seat on Uber's board.
Still, the relationship might be better described as "frenemies" than "partners." Didi's president Jean Liu has said the company is "definitely going global" - -and that inevitably means challenging Uber in other markets (like Brazil, where it announced a "strategic investment" in ridesharing startup 99 in January).
Didi's latest mega-round would give the company more firepower to boost its presence in China and beyond.
Didi's management already had majority control of the company and sources tell CNBC that investors in the new round gave their voting rights to Didi's management.
CNBC reached out to Didi and will update when we hear back.