Aer Arann and Loganair have secured contracts valued at €45.8 million for the latest round of State-subsidised air links to six regional airports.
The public service obligation (PSO) routes were granted after stiff competition from several other airlines, including Ryanair, British Midland (BMI Regional), CityJet and European Express.
The Department of Transport said it was unable to disclose details on the price difference in the bids as this was "commercially-sensitive" information.
Under the new three-year contracts, Aer Arann loses one of the five routes it held during the last PSO round to Loganair, but retains services linking Dublin to Galway, Kerry, Donegal and Sligo.
Loganair, the British Airways subsidiary, takes over from Aer Arann on the Dublin-Knock link, and retains its contract to serve City of Derry airport.
BMI Regional, CityJet, European Express and Ryanair had all bid for Kerry, along with Aer Arann, but Aer Arann was the only bidder for the route serving its home base of Galway.
Both Aer Arann and Loganair had bid for Donegal and Sligo, while the two airlines were joined by BMI and European Express in tendering for Derry and Knock.
Aer Arann will provide three daily return services on the busiest regional routes serving Galway and Kerry, and will provide two daily return services on the Sligo and Donegal routes.
Loganair will provide two daily return services on the Derry route, and one return service each day on the Knock link.
Minister for Transport Martin Cullen pledged his commitment to the regional air routes in spite of proposals several years ago of a possible rationalisation.
A consultancy study by Davy Kelleher McCarthy had analysed the high cost of the State subsidy per passenger on several of the routes.
Mr Cullen said the PSO programme was "vitally important in providing essential air access to the regions" and enabled the Government to contribute to "more balanced regional development" in terms of increased economic activity, tourism and employment.
The announcement has been welcomed by Mr Cullen's Cabinet colleague Éamon Ó Cuív, the Minister for Community, Rural and Gaeltacht Affairs.
Meanwhile, Independent Mayo TD Beverley Flynn has called for capital investment in Knock airport.
She said current constraints on funding Knock "contrasted sharply" with a cash injection of €15 million given recently to Derry airport as part of a cross-Border agreement.
She said State support for Knock would also be "entirely consistent with national and EU policy on regional airport development", and with its position in an Objective One region.
"If it is okay to invest €15 million of Government money on extending the runway at Derry - which includes demolition of several houses - I fail to see why it is not okay to do the same for Knock airport."