Aer Lingus chief executive Mr Willie Walsh has said the airline might consider offering a service to Belfast in the long term.

Mr Walsh, who is anxious to increase the size of the airline's route network, said Belfast was a growing city and the airline would certainly examine the possibility of flying there. He was speaking this week to the BBC.

Aer Lingus has not flown to Belfast for many years, although at one stage passengers from Belfast could link up with the airline's transatlantic service.

The airline also flew to Derry for a period. Belfast International Airport is currently served by four main scheduled carriers: easyJet, bmibaby, jet2.com and Eastern Airways. Most of the airlines concentrate on services to London and various cities in England, Scotland and Europe. There is nobody providing a service between Dublin and Belfast.

Competition from the Enterprise train service and car alternatives have traditionally convinced Dublin-based airlines not to try any Dublin-Belfast services. The presence of easyJet at Belfast International Airport effectively rules out low-cost carriers like Ryanair serving the airport, most observers agree.

However, in June Belfast International Airport revealed it was working to provide additional direct European services by the end of the year.

The airline said talks were underway with airlines to expand air links to mainland Europe. The airport is hoping to reach a record of 4.5 million passengers this year.

Aer Lingus has added a large number of new routes in the last two years, especially in Europe. Its new short-haul Airbus fleet means it can increase frequencies without incurring unacceptable costs.

The airline is also seeking to offer more US services, but this cannot happen until the US and Ireland agree to reform the bi-lateral agreement on air access.