German pilots represented by union Vereinigung Cockpit staged six days of stoppages over the last two weeks, grounding 4,460 flights and disrupting the travel plans of more than 525,000 passengers in a long-running row over pay.

"It's 100 million that we have to deduct due to what's happened in the last few weeks," Spohr said at a conference in Frankfurt on Thursday. He added he expected to enter mediation with the union, which represents 5,400 pilots, before the end of the year.

The union is currently reviewing the latest proposal from Lufthansa, and has ruled out strikes this week while they mull it over.

(Reporting by Ilona Wissenbach; Writing by Victoria Bryan; Editing by Harro ten Wolde)