FRANKFURT, Sept 15 (Reuters) - A German union criticised Air Berlin's administrators for delaying a decision on a carve-up of the insolvent airline until after this month's election, saying it was irresponsible to leave thousands of jobs in the balance.
Administrators are seeking to sell the business, with bids due to be submitted by 2 p.m. (1200 GMT) on Friday. However, a final decision has been pushed back to Sept. 25, the day after Germany's national election and four days later than previously planned.
"This postponement is at the expenses of the workers, who want a decision on their jobs and their future," Verdi union board member Christine Behle said in a statement on Friday.
Air Berlin, Germany's second largest airline, filed for insolvency last month after major shareholder Etihad withdrew funding following years of losses.
Chancellor Angela Merkel's coalition government has granted a 150 million-euro ($179 million) loan to prevent Air Berlin's planes from being grounded.
Air Berlin employs around 8,000 people but it is not clear how much of the company will survive.
Most potential investors are seen as being interested primarily in the airline's roughly 140 leased aircraft and its airport landing and take-off slots rather than its operating business or employees.
Leading German airline Lufthansa plans to make an offer for up to 90 planes, including Austrian unit Niki's fleet and 38 crewed planes it already leases from Air Berlin, a source has told Reuters.
British budget carrier EasyJet is also interested in up to 40 planes, according to previous media reports.
Three-time Formula One world champion Niki Lauda has partnered with holiday firm Thomas Cook's German airline Condor to make a bid worth around 100 million euros for Niki and 17 additional Air Berlin aircraft, the former racing driver has told Austrian media.
Other interested parties include aviation industry investor Hans Rudolf Woehrl, who says he has submitted a bid for the whole of Air Berlin, while German family-owned logistics company Zeitfracht and China's LinkGlobal Logistics have also expressed their interest.
German daily Handelsblatt said on Thursday that the former head of German utility EnBW, Utz Claassen, had put up 100 million euros to buy the carrier and pledged another 600 million in liquidity.
Air Berlin was forced to cancel flights on two days this week after pilots called in sick in unusually high numbers, potentially complicating rescue efforts.
($1 = 0.8391 euros) (Reporting by Maria Sheahan; Editing by Keith Weir)