Didi Chuxing and Uber China, the two biggest app-based ride-hailing service providers in China, have made huge losses in the past two years because of the subsidies they have provided drivers and customers in their competition for market share.

So the deal for Didi Chuxing to buy Uber's China operations, which will see the two on-demand ride providers retain their distinct brands and apps while merging their backends, will help save costs.

However, the deal, announced on Monday, will create a $35 billion ride-hailing juggernaut that will control more than 90 percent of the market, raising concerns that it could take advantage of its dominant position to the detriment of both users and competitors.