US ridesharing service Lyft on Thursday announced an expansion of its alliances with Asian partners in a move that ramps its challenge to Uber.

Lyft , which in September unveiled a partnership with Didi Kuaidi in China, has added Ola in India, and GrabTaxi in Southeast Asia to the alliance, which allows interoperability of the mobile applications in various countries.

Each of the partners' mobile apps will be able to tap into one another's ride sharing services where available and let them call for rides when travelling.

"We're excited to join with Didi, Grab and Ola to make global travel simpler for passengers," said Lyft co-founder and president John Zimmer.

"This isn't solely a partnership of four companies, but also an opportunity to have a greater impact on the future of our cities worldwide."

Working together with Didi, GrabTaxi, and Ola essentially expands each of the service's coverage to 680 cities globally, Lyft said.

Together, the companies cover nearly all of Southeast Asia, India, China and the United States, reaching nearly 50 percent of the world's population, according to Lyft.

Joint products will start rolling out early next year.

"The partnership with Lyft, GrabTaxi and Ola allows Chinese users unprecedented ease of international travel, and helps each of us improve our own services, leveraging our collective technology and expertise," Didi Kuaidi chief executive Cheng Wei said in a release.

"This is a win for the diversity and vitality of the global ride-share industry."

- Sharing local knowledge -

The partners will collaborate on technology, business resources, and knowledge of local markets with a goal of letting travellers get on-demand rides using mobile applications they would use at home, according to the companies.

This means :seamless mobility access across hundreds of cities globally for our combined user base that runs into hundreds of millions," said Ola co-founder and chief Bhavish Aggarwal.

"This will also allow all four companies to learn from each other's local innovations and successes that can help us in our shared mission to build better mobility solutions in our respective markets."

News of the partnerships came as Bloomberg reported that Uber is seeking to raise $2.1 billion in a fresh funding round that would value the US startup at $62.5 billion.

The money would likely be used to fuel global expansion.

Uber said in November that it is planning to expand into dozens more Chinese cities within a year and invest $1 billion as it looks to ramp up market share in the world's most populous country.

Uber this week began letting developers add "ride request buttons" to third-party applications tailored for mobile gadgets powered by Apple or Android software.