The ending of "dual gateway" status would reduce the number of transatlantic flights using Shannon Airport from 50 per week to just seven, according to an analysis carried out by the State agency Shannon Development.
The analysis which Shannon Development's chief executive, Mr Kevin Thompstone, claimed "has not been contradicted by anyone", found that transatlantic passenger carriers invariably fly into European capital cities, but do not have more than one base in that country.
It would seem to contradict the Department of Transport's view that more carriers on the North American routes would be good for all airports.
According to Mr Thompstone, flights into the Republic have grown substantially since the mid-1990s, suggesting that "the current bi-lateral was not a barrier to growth, while it had been a good instrument for balanced regional development". While he believed an "open skies" policy would suit the airlines in that they could reduce costs by flying to just one hub, it would not suit the Shannon region.
Mr Thompstone said there was "nothing pejorative" about his comments. "You don't just run a country to suit airlines. Change is clearly coming and the question is, does changing the bi-lateral to suit the airlines impact on regional development, and clearly it does."
He said that the airport and region could adapt and survive, but only if a package of infrastructural improvements was put in place before the ending of the dual gateway. Mr Thompstone maintained that in a market where "air freight around the world is set to triple", Shannon as an airport with spare capacity could thrive if there was rail access to the airport and a 45-minute travel time between Galway and Shannon.
The Foynes deep water port, the rail, road and air services could make Shannon a global player for foreign direct investment but the options needed to be formally assessed, he said.
However, the incoming chairman of the proposed Shannon Airport Authority, Mr Pat Shanahan, told The Irish Times that while it was true that transatlantic flights currently used only one hub in European cities, the advent of a transatlantic carrier now using Manchester indicated that low-cost airlines were prepared to use second airports in European countries.