CityJet is to discontinue its service from Cork to London City Airport with effect from June 26. The scheduled service just started last October.
The airline's chairman Pat Byrne said that CityJet was faced with the reality that demand for the route had not taken hold in terms of sustainable commercial viability.
Mr Byrne also pointed out that London City Airport is probably one of the more expensive airports in Europe for airlines from an operational standpoint.
He said that the airline has been unable to achieve its passenger load factor and average fare targets.
"Consequently, our 18 weekly flights failed to gain a market foothold sufficiently to ensure a continuity of this service. This is despite strong and appreciated support from Cork Airport and business organisations in the region, in addition to a significant investment in marketing of the route," he added.
CityJet said it is firmly committed to operating its new summer routes form Cork to La Rochelle and Nantes and its charter series to Menorca.
The airline said it will contact all affected passengers who can avail of a full refund.
Customers who booked via a travel agency will be contacted directly by their agency.