Budget airline Ryanair is to close its base at Valencia in Spain with the loss of 70 weekly flights, it has announced.
The move will affect 750,000 passengers a year and 750 jobs in the region will be lost, according to the airline.
It has been prompted by a disagreement with the local authorities over the allocation of marketing funds.
The Irish carrier has been flying from Valencia to 10 destinations around Europe - all flights on those routes will be cancelled from 4 November.
Ryanair blamed the decision on "the refusal of the Comunitat Valenciana to engage in constructive discussions in relation to the promotion of the airport and its routes across Ryanair's network in Europe".
The airline said its investment of more than £85m would be moved to another of its bases, with an announcement expected next week.
The company said it had wanted to cooperate with the tourism department of the Comunitat Valenciana after the announcement of its new Valencia base in August last year.
But a Ryanair statement added: "At the same time as the Comunitat Valenciana was telling Ryanair that no funds were available for such co-operative activity, they were granting a 12 million euro [£9.6m] award of marketing support to the local airline, Air Nostrum, who delivered neither growth nor international passengers to the region.
"Furthermore, the Comunitat Valenciana ignored Ryanair's request for engagement on these important promotional issues and indeed more recently turned down all reasonable requests for meetings."
Ryanair deputy chief executive Michael Cawley said: "This is a very black day for the airport of Valencia and the city and region which it serves.
"Without any assistance or cooperation from the local tourism board, Ryanair has already shown the possibilities which are uniquely available through its low fares."
He added: "However, the naked subsidisation by the Comunitat Valenciana of competitor airlines at the expense of Ryanair and the refusal by the same party to engage in any meaningful discussion with Ryanair have meant that continuation of our base at the airport is untenable."