Grab app. Reuters

Ride-hailing firm Grab has launched what it calls "huge rental discounts" to woo customers from Singapore's largest taxi company, ComfortDelGro.

The offer, which was broadcast to tens of thousands of ComfortDelGro drivers via text message on Sunday night — comes just two weeks after ComfortDelGro announced talks with U.S.-based Uber on a potential tie-up.

The offer include a S$50 rental discount per day, if drivers were to switch to any of its taxi partners - TransCab, Prime, SMRT or Premier.

The discounts are higher if the cabbies take on a private-hire car through Grab's rentals arm, GrabRentals. This will net them a S$1,688 monthly discount, which translates to about S$60 off their rental bill daily.

The discounted rental rates for both schemes apply for six months.

The ride-hailing business is booming in Singapore, with private-hire services such as Uber and Grab making up half the market for point-to-point transport options.

The potential alliance between ComfortDelGro and Uber Technologies includes fleet of vehicles and booking software solutions in Singapore.

ComfortDelGro said the potential strategic alliance with the Uber includes the company's taxis also being made available on Uber's app, among other things.

Currently, Grab has partnerships with all taxi operators in Singapore except for Comfort.

ComfortDelGro shares were down 2.3 percent to S$2.19 on the Singapore Exchange.