The City of Derry airport said it is "reviewing options" to resume a route to Stansted after airline flybmi announced it has suspended flights and is filing for administration.
British Midland Regional Limited, which had operated 17 regional jet aircraft on routes to 25 European cities, said all flights were cancelled from Saturday.
Difficulties have included increases in fuel and carbon costs, as well as challenges “particularly those created by Brexit”, a statement on the airline’s website said.
Flybmi operated a route from City of Derry to Stansted.
The Northern Ireland airport tweeted advice to customers on Saturday evening.
“BMI with immediate effect no longer operate the London Stansted service. If you have seats booked on this service, please contact your credit card company to receive your refund.
“We are reviewing options for resuming the service with another airline as soon as possible.”
The news has been greeted with disappointment in Londonderry.
Derry and Strabane District Council moved to reassure the public.
In a statement on Twitter, the council said: “Very disappointing news that @flybmi have gone into receivership – Council would like to reassure the public that its officers & reps from @CoDerryAirport are in emergency talks tonight with UK Dept for Transport to urgently seek a replacement airline.”
Loganair and Ryanair are currently the only airlines which serve City of Derry Airport.
Last week, Transport Secretary Chris Grayling confirmed the UK Government will continue to provide funding for a flight between City of Derry Airport and London.
East Londonderry MP Gregory Campbell said that he had been in touch with Mr Grayling on Saturday evening over the future of the route.
“Obviously there is concern given that this is the single direct air connection between Londonderry and London,” the Democratic Unionist representative said.
“The Transport Secretary indicated that he is hopeful that a new operator will agree to take on the route.
“There needs to be as seamless a transition as possible from flybmi to the new operator in order that the travelling public suffer as little as possible.”
The public service obligation (PSO) air route, the first of its kind in Northern Ireland, has been in place since 2017.
Mr Grayling said the Government will continue to subsidise the route until 2021.
Sinn Fein councillor Sandra Duffy described the loss of the flybmi flight as a “huge concern for the economy in the north-west”.
She said: “One of the reasons cited by the airline is the uncertainty caused by Brexit – yet more evidence of the destruction and disruption that the DUP and the British Government are prepared to cause to our economy with their reckless Brexit agenda.
“This will obviously have implications for the new public service obligation flight between Derry and London as well as the new route to Manchester, all of which flybmi was due to operate.
“Of course, the loss of the airline does not mean the loss of the service and I have contacted the chief executive of Derry City & Strabane District Council to ensure every effort is made to find an alternative carrier as soon as possible so there is minimal disruption to this service.”