A European envoy held out a possible compromise in a dispute with China over emissions charges on airlines, saying Europe might alter its system if Beijing helps to negotiate a global agreement on controls.

China, India, the United States and Russia oppose European emissions charges on airlines that took effect Jan. 1. Beijing has barred its carriers from cooperating and has suspended purchases of European aircraft to press its objections.

Talks on a global emissions system have begun in the International Civil Aviation Organization, a U.N. body, said Matthew Baldwin, the European Union director of aviation. He said the EU might alter its Emissions Trading System if an agreement is reached.