Lufthansa said it was in talks with Tegel airport in Berlin to secure more slots following news that the opening of the new Brandenburg airport in Germany's capital will be delayed.
"We want to stick with our planned expansion of flights from Berlin," a spokesman for Lufthansa said in a statement.
The airport operator said earlier the opening of Berlin's new airport, scheduled for June 3, would be delayed until after the summer due to problems with fire safety.
Lufthansa has said it plans to increase four-fold the non-stop routes to European and Middle Eastern destinations it offers from Berlin.
"We have noticed in test runs over the past days and weeks that there is still need for action on many matters. It is important for us that smooth flight operations can be ensured at the new airport," the Lufthansa spokesman said.