"Air Berlin Group is one of a few European airlines that fly to long-haul destinations in the western United States and the Far East with only two pilots," -- Vereinigung Cockpit union.

Europe faces fresh air travel disruptions as a German pilots union called for warning strikes at Air Berlin, Germany's second-biggest airline after Lufthansa.

The three-hour stoppage will be sometime in the coming days, pilots' union Vereinigung Cockpit (VC) said on Tuesday.

The move comes a week after VC suspended a strike at Lufthansa that led to at least 900 flight cancellations and left thousands of travellers stranded around the world.

Pilots' union VC said on Tuesday that it is demanding better working conditions for pilots at Air Berlin's charter airline unit LTU. At the core of the dispute are pilots' working hours and staffing on long-haul flights.

"Air Berlin Group is one of a few European airlines that fly to long-haul destinations in the western United States and the Far East with only two pilots," VC said.

A spokesman for Air Berlin said in reaction to VC's strike plans: "We think that this is inappropriate and unusual."