The European Commission told Ireland that it could provide as much as €65.5 million in state aid to six regional airports to fund infrastructure development.
The Commission said the eligible airports were in Donegal, Sligo, Knock, Galway, Kerry and Waterford. Collectively they served a total of 1.3 million passengers last year.
Investment in safety and security can be granted aided up to 90 per cent while and grants for the expansion or improvement of facilities for benefit of airlines or the public is eligible for up to 75 per cent funding.
"The Commission found that the proposed scheme is in line with the community rules as the financing is set to achieve a clear objective of general interest without leading to undue distortion of the market," it said in a statement.
The development of regional airports has increased since the emergence of budget airlines. The trend is seen as a crucial platform to the economic development of the regions and a means fo relieving congestion at hub airports.
But the Commission's concerns about the effect member state funding can have on EU-wide competition meant that funding proposals for regional airports required authorisation.