The use of Knock Airport's State grant for marketing to reduce landing charges, mainly for the benefit of Ryanair, is questioned in the review of operations there produced for the Minister for Public Enterprise, Ms O'Rourke.
The review of the management of the regional airport in Co Mayo has criticised its unrepresentative structure and has said that this could hinder future development.
The review, which was published yesterday, says the airport's deeds of trust do not allow for full representation of the local community in management.
The Minister has called on the airport's board and trustees to "examine how best they might harness local goodwill and commitment".
She has also ordered a review of all regional airports.
The study by the airports division of her Department was undertaken after a meeting between the Minister and "various Oireachtas representatives" for Co Mayo last October, at which "concerns were expressed about aspects of the management and operation of Knock airport".
One of the key criticisms identified in the subsequent review is the use of the airport's marketing grant from Government, running at £570,000, to offer lower airport charges.
This mainly benefits Ryanair, its principal carrier.
The second carrier, British Airways, receives lesser discounts, while no discounts are offered in respect of the new Public Service Obligation (PSO) route awarded to Aer Arann, the report notes.
The report says the practice of granting airport charge discounts has been examined and commented on by the European Commission and its view is that it could lead to distortions in trade if used excessively or incorrectly.
It has said any such discounts offered to build up a new route should be limited in time to a maximum of three years.
"Ryanair's service from Knock airport to London is now a well-established route and has been in operation for over 15 years," the report states.
It says it is not clear there is any marketing value to be gained by continuing to offer discounts.
However, it also says it should be recognised Ryanair would "react strongly, typically by threatening to cease their service from Knock, to any proposal by the airport management to increase the level of recovery of airport charges".
Last month the airport unveiled plans for a £50 million business park that could create up to 2,000 jobs.
