In a statement released on Friday, Lufthansa said it had grounded 74 out of a total 160 inter-continental flights scheduled for Saturday, affecting an estimated 20,000 passengers.

And around 60 percent of Lufthansa Cargo flights would also be hit.

Originally, the pilots' union Vereinigung Cockpit had initially called for a 24-hour walkout on Wednesday, but subsequently extended the industrial action over four days.

The stoppages Wednesday had targeted short- and medium-haul services. Long-haul and cargo flights were grounded on Thursday and then short- and medium-haul flights again on Friday.

In all, around 220,000 passengers have been hit by the four days of
walkouts, Lufthansa calculated.

It is the 12th — and now longest — stoppage since the pilots began their industrial action last April.

The dispute hinges on plans by Lufthansa to scrap an arrangement under which pilots can retire at 55 and receive up to 60 percent of their pay until they reach the statutory retirement age of 65.

Pilots are also concerned about Lufthansa's aim to further develop its low-cost activities as it faces growing competition.