Easyjet - the largest carrier to fly out of Northern Ireland - says it is committed to Belfast International Airport as it celebrates record profits.
The group achieved a 28% rise in profits for the year to September 30 after it carried 58m passengers - an improvement of 7% on a year earlier - and benefited from continuing cost-cutting.
The firm made £317m as higher sales offset a further £182m surge in fuel costs.
Paul Simmons, director of easyJet, said that by staying put and concentrating on growing routes and passenger numbers, easyJet had been able to surpass all expectations.
Aer Lingus moved to George Best Belfast City Airport in October after five years at Belfast International while BA withdrew a service from Belfast International to Heathrow in 2001 before reinstating the route from City after buying out bmi.
"During the time we have been based at Belfast International, we have seen BA go and set up again at City, we have seen Ryanair leave City and we have seen Aer Lingus come to the International and go," he said.
"We have managed to grow and sustain by not being silly. We have a good relationship with the airport."
"For Aer Lingus, we see that as the last throw of the dice. They have gone to George Best Belfast City Airport and how sustainable that is, I don't know," he said.
On future expansion, Mr Simmons added: "We have recently added new routes to Malta, Birmingham and Manchester."
It is hoped the latter flight will help local businesses connect to important markets in Russia after easyJet announced it is to begin a new route between Manchester and Moscow in March.