Vietnam’s trade ministry said on Wednesday it is considering launching a formal investigation into the takeover of Uber Technologies’ South-east Asia business by rival Grab after an initial probe showed the deal would violate antitrust law. Uber Technologies Inc. and its ride-hailing rival Grab Inc. are pressing on with their Southeast Asia consolidation as regulators consider whether a de facto Grab monopoly would harm drivers and passengers. Grab made headlines in March when it announced it was buying Uber’s business in Southeast Asia, driving the ride-hailing giant out of several fast-growing markets such as Indonesia and Thailand.