A union representing pilots at Germany airline Lufthansa is threatening renewed strikes in a long-running dispute over pay.

The Cockpit union said in a release Monday that it will announce within 24 hours how long and how widespread the strikes at the airline, Germany's largest, will be.

The union says Lufthansa has been earning billions of euros but that pilots have been without raises for five years. It's made a claim that seeks to address that fact.

Lufthansa says the threat of a strike is "absolutely incomprehensible" and called for renewed talks, and offered to call in an arbitrator.

The dispute comes as Lufthansa restructures to meet increasing competition from Gulf airlines.