The Vietnam Competition and Customer Protection Authority (VCA) said in a statement that it disagreed with the ruling of the Vietnam Competition Council (VCC) on June 17, saying the acquisition has led to Grab controlling Uber’s operations in the country, which is a violation of the law.

VCA is under the Ministry of Industry and Trade, while VCC is independent of the ministry. The Competition Law states that if any merger or acquisition leads to a 50 percent market share for a company, it can only be carried out with official approval.

VCA's statement came after the Vietnam Competition Council had said the Grab-Uber deal in Vietnam did not involve equity. Grab did not have voting rights in Uber Vietnam after the transaction, it had said, adding that the Netherlands-based Uber B.V. continued to operate the Uber app after the deal, not GrabTaxi.

Citing this reason, it had ruled that the Grab-Uber deal did not violate antitrust laws, and asked the VCA to pay case fees of VND100 million ($4,300).

The VCA’s appeal means Grab could again be embroiled in a legal tussle. Grab insists it acted legally and the competition authorities misinterpreted the scope of relevant markets when calculating market share.

Singapore-based Grab’s acquisition of Uber’s Southeast Asia operations in return for a 27.5 percent stake in March last year had alarmed authorities in Vietnam and other Asian countries about possible contravention of antitrust laws.

The Philippines’ competition watchdog fined the two companies a cumulative 16 million pesos ($296,900) saying they had completed the deal too soon and that the quality of service had dipped.

The Singaporean competition authority fined them S$13 million ($9.5 million) and announced other measures to address competition concerns arising from the merger.