Taxi booking app Karhoo has added a second fleet of taxis to its platform, after having already secured an agreement with ComfortDelGro, reported The Straits Times.

A source close to the British start-up, which aims to launch here early next year, told The Straits Times it had inked a second deal with Prime, the island's smallest operator with over 850 taxis.

The Karhoo app lets commuters pick a cab across companies, based on criteria such as price, time of arrival and type of vehicle. They are given a choice of taxis nearest to them.

While taxi apps, such as GrabTaxi and Hailo, work through peer-to-peer matching of cabbies and passengers, Karhoo works by relaying its customers' booking requests to the cab operators' despatch systems.

An industry observer, who requested anonymity, said Karhoo will now have to work with the cab firms to get its app and the operators' despatch systems integrated.