Aer Rianta is suing Ryanair over an alleged claim by the private airline in a press release and on its website that Aer Rianta was levying a higher passenger service charge than the amount of the actual charge.

Aer Rianta also claims Ryanair unjustly enriched itself by pocketing the amount of the alleged increase through a rise in Ryanair's own "applicable taxes" on passengers. Aer Rianta claims Ryanair issued a press release and falsely published on its website in 2001 that Aer Rianta was levying a passenger service charge of £9.50 in 2001 when the approved rate was £7.23.

Yesterday, Mr Justice Lavan reserved judgment on Ryanair's application that part of Aer Rianta's claim be struck out. That concerns a claim that Ryanair was allegedly unjustly enriching itself insofar as it had overstated to passengers the level of "airport charges" and did not pass on the full amount to Aer Rianta.

Mr John Breslin, for Ryanair, said Aer Rianta's claim that the airline company was unjustly enriching itself should be struck out as it disclosed no reasonable cause of action in law. Ryanair's case was that Aer Rianta was claiming to be entitled to restitution but there were no pleas by Aer Rianta that the alleged unjust enrichment was at its expense.