United Airlines will suspend its New York to Belfast service for three months from January 2015.
The route, which is the only direct link between Northern Ireland and the US, will be affected from January 6 until March 15.
The decision follows a “company-wide review” by United.
The airline has also suspended some other transatlantic routes from Dublin, Rome and Manchester.
Belfast International said in a statement that it was “naturally disappointed” that it is one of four European airports to be affected.
“We have been kept fully informed by United who assure us that it is their intention to resume normal service on the Belfast-Newark route from the 11thMarch next year,” the airline said.
“This is a successful route for United but performance is not traditionally as strong in the first couple of months of the year.
“United has contributed massively to the Northern Ireland economy over the past decade and we know it will continue to provide a vital link for business, and support continuing efforts to attract inward investment, for the remainder of 2014 and over the New Year period, and again when the service returns in March 2015.”
United.com