Consumers in Northern Ireland will be the big winners as Aer Lingus' move to its new hub at Belfast International Airport looks set to push down fares for travellers.
The Dublin-based airline was to confirm today that it will be undertaking a multi-million pound investment at Aldergrove to create its first base outside the Republic.
Aer Lingus, which markets itself as a low-cost carrier offering a full service, will initially serve eight destinations from Belfast - and its arrival in Northern Ireland is expected to drive down fares.
Among the routes are Barcelona and Malaga, both of which are already serviced by low-cost carriers easyJet and Jet2.
And it will also go head to head with easyJet on routes from BIA to Amsterdam, Faro, Geneva and Rome.
In addition Aer Lingus is planning to take on bmi on the Belfast-Heathrow route.
Bmi, which offers eight flights a day, has enjoyed a monopoly on the Heathrow route from Belfast City Airport since British Airways pulled out in 2003.
Aer Lingus will offer three flights a day, including a late flight from Heathrow to the province. Bmi has wanted to establish a late flight from Heathrow for some time, but is prevented from doing so by planning restrictions at the City Airport.
The availability of a late flight from Heathrow with Aer Lingus could prove to be tempting for business passengers in particular.
At present they have to leave central London before 5pm if they want to catch the last flight home from Heathrow.
London Heathrow slots from Shannon Airport in the west of Ireland will be axed to make way for Belfast.
Aer Lingus chief executive Dermot Mannion met with staff at Shannon earlier today to explain the airline's decision.
The Irish carrier has a large load factor on the Shannon-London route, but yields are believed to be poor.
The only route, meanwhile, where Aer Lingus will not face competition is Belfast-Budapest.
Aer Lingus will take off from Aldergrove in December with flights to Amsterdam, Barcelona and Geneva.
It will then be chocks away for the Heathrow link in January, followed by Budapest, Faro, Malaga and Rome in February.
An Aer Lingus service between Belfast and New York is another possibility. It could be established as early as next spring.
First Minister Ian Paisley and junior minister Gerry Kelly were due to welcome Aer Lingus chiefs to Parliament Buildings at Stormont today for the official unveiling of its new routes.
The Irish airline was also expected to announce plans allowing passengers to travel onwards with British Airways and Dutch carrier KLM from their London and Amsterdam hubs to destinations worldwide.
Hundreds of new jobs will be created by its decision to base three aircraft in Belfast.
Apart from the three flights a day to Heathrow, there will be two daily flights to Amsterdam. The other six destinations will have two to five services a week.
The move could boost passenger numbers at the International Airport by 800,000 a year to nearly six million annually.
Belfast fought off competition from Birmingham for Aer Lingus' investment.
Invest Northern Ireland is ploughing £2m into the multi-million pound initiative.
A Belfast Telegraph price comparison showed a return flight per person to Barcelona with easyJet between December 13 and 18 this morning cost £51.98 including taxes (Dec 15-17), while a return flight with Jet2.com on the same route would cost £35.18 (Dec 13-18). With Aer Lingus entering the market and competition increased, these prices could fall even lower.