Transport Minister Martin Cullen has announced funding of €6.4m for the country's six regional airports under the National Development Plan.
Knock and Waterford will receive around €2m each, while Donegal will be allocated €1m. Galway, Kerry and Sligo receive the remainder.
The airports received €9m under a first round of grants between 2002 and 2004. An additional €6m could be given following analysis of plans for runway improvements at Sligo and enhanced navigational aids at Knock.
Minister Cullen also announced that a tender process for contracts to run Public Service Obligation (PSO) air routes between Dublin and regional airports has begun. The new contracts will run for three years from July 2005 and the successful bidders will be announced in mid-May.
Liam Scollan, CEO of Knock Airport welcomed the funding announcement. He said the €2.013m grant will be used for projects related to safety and security only.
He added that over the next three years, Knock airport needs to invest a further €18.7m to meet the growth in passenger demand and that one of the key investments will be CAT II landing capability which will cost around €6m.