FRANKFURT, Oct 6 (Reuters) - Air Berlin and labour unions called on the German airline's workers to put in extra hours to offset staffing shortages at TUI's carrier TUIfly , pilots' union Vereinigung Cockpit (VC) said.
Air Berlin leases some planes, including crew, from TUIfly, so any staff shortages also affects its operations.
Pilots and crew at TUIfly have been calling in sick this week, forcing the cancellation of dozens of flights, following news of plans to merge TUIfly with Air Berlin's leisure travel business.
Workers at TUIfly are concerned that a combination with part of Air Berlin in a holding led by Abu Dhabi-based Etihad, Air Berlin's biggest shareholder, could mean job and pay cuts, union Verdi said this week.
TUIfly earlier on Thursday said it had chartered 18 aircraft from other airlines to try to keep operations going, but it still had to cancel 47 of a planned 110 flights scheduled for the day because of staff calling in sick. Air Berlin, unions VC and Verdi and the works council are asking Air Berlin's pilots, cabin crew and ground staff to work extra shifts, the pilots' union said in a statement on Thursday. (Reporting by Maria Sheahan. Editing by Jane Merriman)