Budget airline Ryanair said this morning it had lodged an appeal against a European Commission order to repay some Belgian subsidies it received for its European hub operations at Charleroi, south of Brussels.
The European Union executive ordered Ryanair in February to repay millions of euros in subsidies, saying some of the handouts for using the state-owned regional airport broke EU law.
An appeal to the EU's Court of First Instance normally takes about two years to produce a decision.
At that time, Ryanair chief executive Mr Michael O'Leary denounced the Commission decision as a reversal of 20 years of competition and low fares in Europe, although rival budget airlines welcomed the ruling.
The Commission declined to put an exact figure on the amount to be repaid but EU officials estimated it at less than €4 million.
Shares in Ryanair lost almost one-third of their value at the end of January after the carrier shook investors with its first profit warning.
Mr O'Leary vowed this month not to increase fares this year despite a rise in jet fuel prices that has prompted other airlines to charge a fuel surcharge.