The company that co-ordinates flights from Dublin Airport has sanctioned Ryanair over its refusal to operate its services within a new management system at the heavily-congested airport. Arthur Beesley, Senior Business Correspondent, reports.

Airport Coordination Ltd, which acts as agent for the aviation regulator, moved last Wednesday to withdraw the allocation of gates in the airport's departure lounge for all Ryanair flights to Frankfurt-Hahn.

As a result of this action, Ryanair has had to use some of its other departure gates on an ad hoc basis to bring passengers to its planes. "They are circumventing this by working the system internally to enable them to take off," said one figure.

Air Traffic Control continues to manage the actual departure of the flights to Frankfurt-Hahn, but aviation sources believe the co-ordinator's action greatly compromises the airline's ability to fly its planes according to the advertised schedule for the route.

A spokeswoman for Ryanair would not discuss the withdrawal of gates for the Frankfurt-Hahn service or any other aspect of its dispute with the regulator. "You wouldn't want to believe everything that you hear. Ryanair's expansion will proceed as scheduled," she said.

There was no comment last evening from a spokesman for the regulator, Cathal Guiomard, who referred queries to the head office of Airport Coordination Ltd in Heathrow.

The co-ordination company did not return calls and the Dublin Airport Authority said only that slot co-ordination was a matter for the airlines and the regulator. However, it is believed that a meeting between the airline and the co-ordinator has been scheduled for next Tuesday.

The regulator introduced a capacity management system at the end of March to govern the flow of passengers through departure areas that are frequently over-crowded. Under this "fully co-ordinated" system, every flight from the airport is allocated a specific slot within a timetable for the use of departure gates.

The management of this system is separate to the air traffic control function, which governs when planes take off and land.

Before full co-ordination was introduced last month, the allocation of slots was a matter for airlines themselves.

In advance of full co-ordination, Ryanair was allocated morning slots for new services between 5am and 6am. This amounted to a big inconvenience for the airline, which is expanding its services from Dublin and which would prefer to operate flights in the peak period between 7am and 9am.

Ryanair is taking legal action against the aviation regulator on the issue.

It believes that it is becoming impossible to add services to the airport at peak times.

The withdrawal of gates for flights on one route carries with it the implicit threat that gates for other routes would be withdrawn if the dispute is not resolved.

Such a manoeuvre would have the potential to significantly disrupt other services at the airport.