Ryanair has agreed a new deal at Belgium's Charleroi airport and has said it will keep flying all of its 11 routes from the airport.

The Irish airline has been in negotiations with the airport's owners, the Walloon Regional Government, since its previous deal was outlawed by the European Commission in February after it was deemed to have benefited from illegal state-aid.

In a statement, Ryanair said that the existing airport and handling charges would continue for the foreseeable future, and that it was now exploring the possibilitiesof basing more aircraft at Charleroi. The airline had threatened to abandon the airport after the Commission ruling.

Yesterday, Ryanair chief executive Mr Michael O'Leary said it had negotiated a number of other airport base arrangements in recent months at costs that were lower than at Charleroi and that it was considering switching that base. "These lower-cost alternatives again highlight the flaw in the recent European Commission decision on the cost-base at Brussels Charleroi," he said.

The airline claimed it will continue to pay the existing airport and handling charges until the airport reaches two million passengers a year, at which time third-party competitive handling will be introduced. New legislation will be introduced by the Walloon authorities to ensure that the discounted arrangements offered to Ryanair, which accounts for more than 80 per cent of its business, will be made available to other airlines.

A European Commission spokesman said it had not received information about the terms that had been agreed between the airport and Ryanair, and it was still awaiting the Belgian government's response to its February ruling. Ryanair has appealed the ruling which could result in Ryanair repaying at least €4 million to the Walloon Regional Government.

The Commission said the deal, which had been agreed for 15 years, should be shortened to five years. It also said that Charleroi could offer reduced handling charges only where it can show that these discounts are not being subsidised by public monies.

Yesterday, Ryanair maintained that this new arrangement is in line with the private investor principle used as a yardstick for the deals by the Commission.

"When Ryanair appeals the decision to the European Court of First Instance in early May, this principle will form the core of our appeal," Mr O'Leary said.