Uber may have left South-east Asia for good but the region's US$5 billion (S$6.6 billion) ride-hailing field is by no means wide open for its victorious rival Grab, with home-grown players lining up to challenge Grab in their own countries.

South-east Asia is also uneasy over Grab's virtual monopoly, with the deal to acquire Uber drawing immediate and careful scrutiny from regulators in Malaysia, Singapore, the Philippines and Vietnam.