Uber, the car-service booking app maker, is reportedly in talks to secure funding that would value the company at more than $10 billion.

According to Bloomberg sources, the San Francisco-based start-up established in 2009 is in talks with new private equity investors to raise funding that is believed to be less than $1 billion, although the exact value has yet to be confirmed.

The sources said the funding sought by Uber will be used to boost growth and the company’s operations.

Uber was valued at $3.5 billion last year, when it secured a funding round of $258 million. The company has raised a total of $307.5 million since it was founded, with investors including Google Ventures.

Uber offers a range of car services, ranging from high-end (UberLux and UberExec), to the lower-end UberX. The service is available in 112 cities in 35 countries, with Rio de Janeiro, Perth in Australia and Riyadh in Saudi Arabia among the most recent launches.

Speaking at this week’s Open Mobile Summit in London, Jo Bertram, Uber’s general manager for UK & Ireland, said that in each new city in which the service has launched, uptake has been more rapid than the last. “We’ve seen phenomenal growth since we launched in San Francisco,” she noted.

“We believe that in any city where people need to get around, this is an app that can add value,” she added.

The service hasn’t always been welcomed by local regulators or taxi drivers, who fear it will negatively impact their work.

Trials of taxi-hailing apps in New York City were temporarily halted last year because cab companies argued that using the apps to book taxis count as pre-arranging a service — something they felt is part of their remit.

And next month, around 10,000 taxi drivers are expected to protest against Uber in London, with other protests due to take place in Europe.