Lufthansa is interested in operating low-cost long-haul flights from Berlin under its Eurowings brand, as it seeks to win a bigger share of the budget travel market.
"Berlin could also be an interesting market... At the moment we are negotiating opportunities," chief executive Carsten Spohr said at an event to mark 25 years since Lufthansa was allowed to restart flights to Berlin with Germany's reunification in 1990.
He said that as the market in Berlin was particularly price-sensitive the capital could be a good base for Eurowings to operate out of in the future, although for the moment it was concentrating on flights from Cologne.
Eurowings aims primarily to win back market share lost by Lufthansa to European low-cost rivals Ryanair and easyJet but will also operate two long-haul aircraft this winter, flying direct flights to Cuba, the Dominican Republic, Dubai, Bangkok and Phuket.
With Berlin's new airport delayed and its two existing smaller airports operating at full capacity, launching new routes won't be easy.
"If you have an interesting project, you'll always find a space in Berlin," Spohr told reporters.
Karsten Muehlenfeld, chief executive of Berlin's airports operator, said at the same event that the city's airports did have a couple of runway slots free and that long-haul flights were the preferred option for the slots.
Asked about Ryanair's recent suggestion that Europe's main scheduled airlines leave it to the budget carriers to provide the short-haul connections for their long-haul services, Spohr said this was not Lufthansa's strategy. Instead the German carrier wanted to ensure it provided a premium service for its hubs in Frankfurt and Munich, where it still operates short-haul flights under the Lufthansa brand.
"We don't want to change that, but as Europe's largest airline it never hurts to have talks with successful rivals," he added.