Singapore's antitrust watchdog says the Uber-Grab merger hurts competition and is considering a fine and other remedies.
The remedies include removing "exclusivity obligations" on drivers and selling Uber's car rental service in the country.
If those remedies aren't enough, the Competition and Consumer Commission (CCCS) may require Grab and Uber to unwind the merger.
Uber agreed to sell its Southeast Asia businesses to regional rival Grab in March, in exchange for a 27.5 percent stake in Grab. In addition to Singapore, the deal applied to Uber's businesses in Cambodia, Indonesia, Malaysia, Myanmar, Philippines, Thailand and Vietnam.
Singapore's antitrust watchdog launched a rare investigation into the merger shortly after it was announced, Reuters reported.
The regulator does acknowledge that a reversal may be impossible because Uber transferred its assets to Grab immediately after the deal was sealed.
Grab said the CCCS took a narrow approach in its definition of competition. The company plans an appeal.
"While we are one of the most visible players in transport, we are not the only player in the market. CCCS has not taken into account the dynamic developments and intense competition going on over the past few months, from both new and incumbent taxi and ride-hailing players," a spokesperson said in a statement.
Grab also "proactively proposed voluntary commitments ... to ensure consumers' and drivers' interests are taken care of, which the CCCS had rejected," the spokesperson said.
Uber directed a request for comment to Grab.
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