Bmi will drop two flights from its five-times daily Heathrow-Berlin Tegel service by October 30.
The A320 aircraft made available will be redeployed on to new routes to Nice and Agadir.
The carrier increased the frequency on its London-Berlin route to five-times daily in June last year, but will now drop one daily flight (BD847 and 848) from August 25, followed by another (BD841 and 842) from October 30.
This will leave three daily flights on the route, departing Heathrow at 1200, 1710 and 2210, and leaving Berlin at 0825, 1340 and 1845.