BERLIN (AP) — Bankrupt German airline Air Berlin has canceled dozens of flights, citing an "unusually high" number of pilots calling in sick.

Germany daily Bild reported Tuesday that the airline is in a dispute with pilots about the transfer of staff to a potential buyer.

Air Berlin declared bankruptcy last month following years of losses and the decision of its biggest shareholder, Gulf airline Etihad, to cease payments.

Bids to take over Air Berlin must be submitted by Friday.