Low-cost Irish airline Ryanair announced on Thursday that it will stop serving the German cities of Dortmund, Dresden and Leipzig next year.
The airline will also reduce its routes to Hamburg by 60% and to the capital, Berlin, by 20%.
The decision follows a dispute with the German government over an increase in taxes, which would make flights within Germany more expensive than elsewhere, according to Ryanair.
The Irish company predicts that the number of passengers in Germany will drop by 12% next summer because of this measure. This represents a reduction of 1.8 million seats.
Ryanair argues that the rise in air taxes, along with growing costs for security and air traffic control, is untenable. The airline is urging the government to immediately abolish air taxes, reduce air traffic control costs, and delay the increase in security-related fees.
Ryanair currently offers flights from Brussels Airport to Berlin. It is unclear if these will continue next year.
German airline Lufthansa, the parent company of Belgian carrier Brussels Airlines, has also expressed concerns about rising costs in Germany. Low-cost competitor EasyJet has already reduced its services in the country.
