Ryanair may seek to change the take-off and landing slots it has been allocated at Dublin airport after a High Court decision went in its favour yesterday.

At present, Dublin airport has a co-ordinated system where a UK company - Air Co-ordination Limited - allocates take-off slots to airlines, rather than a voluntary system where the airlines are not bound by the directions of the co-ordinator. This is known as the "schedule-facilitated" system.

The Commission of Aviation Regulation, which made the decision to bring in the new co-ordinated system, said it was studying the High Court judgment. It is likely to appeal the judgment however.

Jim Callaghan, head of regulatory affairs at Ryanair, said the company had yet to make a decision on whether it would demand changes in slots for the remainder of its summer schedule, but he said it was clear the current system had been "annulled".

He said previous aviation regulator Bill Prasifka had "jumped the gun" by making Dublin airport a co-ordinated facility. He said this should only be done as a last resort when there was no other measure that could be taken to deal with the problem. He said "mismanagement" of existing runways and terminals was the key problem.

Take-off and landing slots is a key issue for all airlines at the airport. Airlines like to get as many airlines into operation during the morning peak as possible.

If Ryanair seeks to have slots changed, it is likely to face resistance from other airlines, which also want to maximise take-offs and landings during peak periods.