SINGAPORE - Regulators are prepared to step in to ensure that ride-hailing firm Grab's acquisition of rival Uber's South-east Asian business does not erode competition or result in a monopoly.

The Competition Commission of Singapore (CCS) said on Monday (March 26) that if it saw this happening, it could ask for the merger - which both Grab and Uber confirmed on Monday - to be modified, or even unwound.

The Land Transport Authority said it was also watching the development closely.

"We will ensure that no one single market player dominates the sector to the detriment of commuters and drivers," it said.

Meanwhile, taxi giant ComfortDelGro, which had entered into an alliance with Uber, said it is now reviewing "all aspects of its proposed tie-up" with the American firm.

The CCS said competition laws prohibit mergers that may result in a substantial lessening of competition, and indicated that it could "require the merger to be unwound or modified" or it could also "consider issuing interim measures prior to the final determination of the merger".

A Grab spokesman said: "We will make a merger notification to the Competition Commission of Singapore."

She added that the company had also informed the Land Transport Authority of its acquisition, which includes Uber's food delivery businesses.

The Grab spokesman said UberFlash - an app Uber launched with ComfortDelGro - will cease on April 8 while the UberEats app will run until the end of May.

ComfortDelGro spokesman Tammy Tan said: "We are reviewing all aspects of the proposed tie-up with Uber Technologies, which is currently under review by the CCS."

The LTA added that it was reviewing a regulatory framework to license private-hire car operators.

"The strategic intent is to keep the private-hire car and taxi industries open and contestable," it noted.