The Sunday Times reported that the Irish airline was shortly to unveil its plans for Belfast, and that part of the deal would be the launch of new transatlantic services from Aldergrove.

It said the airline was expected to base two new Airbus 320 aircraft at Belfast International, and use them for routes to the US.

A spokesman for Aer Lingus in Dublin said: "We are still looking at a number of options and are in discussions with a number of airports. As yet we have made no final decision."

Uel Hoey, the business development director at Belfast International, said: " We are still talking to Aer Lingus and as yet no decision has been made.

"We do, however, remain hopeful of a positive outcome to our discussions."

In June it was reported that Aer Lingus was trying to decide between Belfast and Birmingham as the location of a new UK hub.

At the time, DUP transport spokesman Jeffrey Donaldson said Belfast International was "moving ever closer" to attracting Aer Lingus.

Mr Donaldson, the Lagan Valley MP, said that if the airline set up shop at Aldergrove, it could ultimately result in the opening of 15 new routes to Britain and the Continent as well as the reinstatement of a link between Belfast International and London Heathrow.

Belfast International, which is owned by Spanish company Abertis, now handles five million passengers a year and is a major hub for easyJet.

According to the Sunday Times, Aer Lingus believes Belfast is more accessible now than ever to passengers from the Republic, thanks to improved road and public transport links.

Last month it was disclosed that Ryanair was on the brink of signing a deal to start flights from George Best Belfast City Airport.

But the airline has yet to come forward with a public statement, while Belfast City Airport describes the reports as "speculation".

Last week, Ryanair announced the launch of 11 new routes from several different European bases, but Belfast was not on the list.

If Aer Lingus does launch a service from Aldergrove to Heathrow, it will be in direct competition with bmi's eight flights a day service from Belfast City.

But the possibility also emerged recently of British Airways re-starting the route from Aldergrove, which it axed in September as part of the fallout from 9/11.

Willie Walsh, the BA boss who used to run Aer Lingus, told the Northern Ireland Chamber of Commerce in June that he would "love" to reinstate the route.

He said he regarded the service as having been "suspended" rather than axed, but said its revival hinged on an increase in runway capacity at Heathrow.