Aer Lingus is expected to announce on Tuesday that it is to drop its twice daily Heathrow - Shannon service and transfer the slots to a new Belfast International (Aldergrove) route.
Ryanair continues to operate out of Shannon, but Aer Arann also serves many destinations in western Ireland, including Donegal, Sligo, Galway and Knock, among others.
In another move, Aer Lingus has inaugurated a four times per week Dublin - Washington DC operation. Washington is the first of Aer Lingus' three new US long haul routes in 2007, with flights to Orlando and San Francisco commencing in October.
While the new EU-US Open Skies agreement does not fully come into effect until March 2008, the Irish Government secured the right for Aer Lingus to start flying to three new US gateways in 2007 ahead of all other EU airlines.
Hailing the inaugural flight to Washington DC as a watershed in Ireland's aviation history, Aer Lingus chief executive, Dermot Mannion, said: "The removal of constraints on Aer Lingus' expansion into the US is hugely significant for both the airline and the country.
”More than one million North Americans visited Ireland in 2006 with a spend of ”800m (”544m) and Tourism Ireland expects these numbers could grow to 1.6m visitors with a spend of ”1.26bn over the next six years thanks to Open Skies.”
Aer Lingus has recently taken delivery of two Airbus A330, the carrier”s first new long haul aircraft in six years.