At least three airlines are in discussions with Belfast International Airport about a new air route to the United States.
The negotiations follow the end of Northern Ireland's only daily direct flight to the US.
US carrier United Airlines made its final departure from Belfast International Airport with 150 passengers on board.
United Airlines flight UA 76 to New York took off at 12.12pm, marking an end to the region's only direct US air link.
The flight departed 50 minutes behind schedule following a delay in the earlier arrival of the final inward flight from New York to Belfast.
It is understood that negotiations are ongoing with at least three other airlines to open a direct transatlantic route. Low-cost carrier Norwegian Air is believed to be one of the airlines involved in discussions.
A spokeswoman for Belfast International Airport said: "We are in discussions with a number of airlines to replace the route."
Economy Minister Simon Hamilton said he continues to work closely with the International Airport to explore other possible air routes to North America.
He added: "I am pleased that we have been working together on some options. I also intend to announce the establishment of a new Air Routes Task Force in the coming weeks and that will help us to identify key routes that Northern Ireland's airports should be targeting and suggesting possible policy interventions and initiatives to attract airlines."
As passengers arrived at the check-in desk for the final New York flight many spoke of their disappointment that the air route - which they saw as a direct link to family and friends - had been stopped.
However, airport managing director, Graham Keddie, insisted they are working closely with government to deliver a major long-haul project that would "open up attractive additional and badly needed connections".
The US airline announced last year it would stop flights between Belfast and New York. It said it made the decision because of the route's poor financial performance.
A £9 million rescue deal agreed by Stormont and the airline fell through because the financial package breached EU state rules.
The route between Belfast International Airport and Newark first began in 2005, operated by Continental Airlines.
United took over the operation of the route in 2012 following a merger between it and Continental Airlines.
John and Dorinda Kildea and their son Corey, two, who are originally from Northern Ireland, were travelling back to Philadelphia after spending Christmas with family.
John said: "We come home two or three times a year and this was the flight we used. It is disruption for us now, it's a blow. I guess we will be looking at the Dublin flight now."
Haig Dick, originally from Islandmagee, Northern Ireland, said: " I live in Long Island, New York, and would use this flight three or four times a year. It was a direct link to my family."
Elizabeth Watford, from Londonderry but now lives in Virginia, was flying back to the US with her sister, Ann Dagenais.
She said: "I'm hoping they will find another direct flight before we come back again. It's sad."
Speaking as the last United Airlines flight departed, Mr Keddie said talks are ongoing in relation to future plans for transatlantic services.
He said the departure of United Airlines was a "big loss for the Northern Ireland access to the US market".
"Over one million people used the service in the eleven-and-a-half years it has been operating.
"We see there is a definite market here. It is disappointing United is leaving," said Mr Keddie.
Passenger growth rates at Belfast International Airport increased by 17.2% last year, with 5.15 million passengers.
December saw a record growth of more than 33% and the airport has achieved monthly double-digit growth since July last year.
This year, passenger numbers are expected to be in the region of 5.4 million.