Aer Lingus has said the travel disruption caused by the Icelandic volcano has so far cost the company between €15m and €20m.
In a statement to the stock exchange the airline said the grounding of flights is costing between €4m and €5m daily as a result of passenger disruption and lost revenue.
In the first five days 1,100 flights were cancelled.
The airline however said it has substancial cash reserves and can withstand a sustained closure of airspace.