Ryanair has agreed to repay €4 million to the Walloon government until the airline's appeal is heard and the European Courts make a definitive decision on the matter.
The Walloon region and Charleroi Airport have sought the return of the €4 million following a decision by European Union regulators in February that incentives received by Ryanair for setting up a hub at the airport were illegal.
Ryanair is appealing the ruling.
If Ryanair is successful in its appeal, these funds along with interest will be returned to Ryanair. If the appeal fails, these funds will be transferred to the region.
Ryanair's head of communications, Mr Paul Fitzsimmons, said that the airline is "confident" that the decision of the European Commission will be overturned by the European Court and that the court will promote the "enormously successful partnership between low fares airlines and regional airports".