Budget airline Ryanair is to terminate its route from Brussels Charleroi to London with effect from 29 April.
Ryanair was given aid to fly from Charleroi
Earlier this month the European Commission said it would fine the low-cost carrier for receiving illegal incentives to use the Belgian airport.
Ryanair confirmed its route decision had been made in light of the ruling, which it had called "a disaster".
The airline operates eight Charleroi- London flights daily; the cut means a 10% drop in flights from Charleroi.
The airline said it was the first element of its response to the European Commission's recent decision to "increase costs at Charleroi and require that Ryanair's passengers should pay higher fares".
Ryanair will appeal against the decision at the European Court in Luxembourg.
But while this appeal is under way, there will be reductions in flights and services at Brussels Charleroi, it said, as aircraft capacity is reallocated to other lower cost airports.
Ryanair's chief executive, Michael O'Leary, said: "These capacity reductions are bad news for customers at Brussels Charleroi, but good news for other lower cost airports.
"As the Brussels-London route had the lowest fares, this route cannot be sustained if costs are to be increased as a result of the Commission's decision to increase ticket prices by six to eight euros per ticket."
He said the flights would now operate on routes between private airports such as London Stansted, Glasgow Prestwick, Stockholm Skavsta and London Luton.
The European Commission had ruled some of the hand-outs paid to use Charleroi broke EU law.
Ryanair will have to return about 4m of 15m euros in state aid it received from the local Walloon authorities in Belgium.
Mr O'Leary said Ryanair would soon be meeting with the
airport authorities and Wallonia regional government to discuss a way forward.