Stobart Air has said it will cease operations from Shannon Airport on 5 January.
Stobart Air is the franchise partner of Aer Lingus operating flights under the Aer Lingus Regional brand.
It operates flights from Shannon to Bristol, Birmingham and Edinburgh under this franchise. This decision will mean the loss of 20 flights a week to these destinations.
The airline's passenger number on these routes increased by 43 per cent in September compared with the same month last year.
The company said, "This is a regrettable decision and not one taken lightly. Shannon does not fit with our current strategic plan and we have to amek the right long-term choices for the airline."
The company added that passengers who have booked for after 5 January would be contacted by the airline and rebooked on alternative Aer Lingus Regional flights or given a full refund.
The company also said that Shannon-based Stobart Air employees would have the opportunity to be redeployed within the company.
Shannon Airport said, "The decision is outside our control and we are already in talks to secure replacement carriers for these services and are assisted by the fact that these routes have delivered strong passenger numbers."
Shannon Airport has been enjoying considerable growth this year and is on course for double-digit growth.