Thousands of Norwegian Air passengers face travel uncertainty following the sudden announcement that it is cancelling all transatlantic routes.
Six routes between Dublin, Cork and Shannon and New York, Boston and Toronto will wind up on September 15 following a decision by the airline to shut its Dublin base.
A spokesperson said several thousand customers will be offered refunds.
Alternatively, they will be given the option of flights via London or Scandinavia.
Industry insiders said many getting refunds would have to pay much higher prices for tickets on competitor airlines at this time of year, while it would take longer for passengers to fly via other bases.
In addition, those going for this option have no guarantee they will be flying on the same day they had booked.
Up to 134 pilots and cabin crew jobs are at risk following the decision, taken after a review of the airline's operations.
A spokesperson said it is "proactively engaging" with unions for pilots and cabin crew to ensure redundancies "remain a last resort".
Eighty Dublin-based administrative workers will not be affected by the route closures.
In a statement, Norwegian Air said the routes are no longer commercially viable.
It has also been affected by the grounding of Boeing 737 Max aircraft.
The loss of the North American routes came to light as thousands of Ryanair passengers face the threat of strikes next week if last-ditch talks fail to end a row with its pilots.
Trade union Forsa has accepted an invitation to discussions today issued by mediator Kieran Mulvey over its pilot branch's claim for improved wages and terms and conditions.
However, a spokesperson said a "substantive and meaningful" proposal from management will have to be tabled to prevent strike action.
It is understood the union is planning a number of one-day strikes that could coincide with stoppages by UK-based Ryanair pilots next Thursday.
It was set to serve notice of industrial action yesterday if the airline did not accept its demands by a deadline on Monday, but it pulled back following the invitation to talks.
Ryanair operates around 230 flights a day in and out of Dublin, which could carry up to 43,000 passengers when full at this time of year.
However, it only grounded a portion of flights last year when hit by industrial action, as agency and contracted staff kept services running.
The strike threat could mean further turbulence for the airline as pilots and cabin crew in other countries have already announced stoppages this month and next. They include:
Ryanair said the industrial action has no mandate and is ill-timed due to Brexit.