A Lufthansa Airbus A380-800.

Berlin - Lufthansa ruled out on Friday any concession to pilots, whose three-day strike to demand better pension benefits forced cancellation of 3,800 flights.

The German flag carrier said it expected to resume flights quickly Saturday after the unionised pilots return to work at midnight (00:00 SA time) Friday.

Only about 190 pilots and 100 managers with pilot's licenses defied the strike and flew during the stoppage.

Lufthansa and its Germanwings budget subsidiary employ about 5,400 pilots.

They are demanding the revival of a pensions deal that let them retire at will from age 55 on 60-per-cent pay.

Kay Kratky, chief of passenger operations, told reporters in Frankfurt that a company offer to the union last week contained sufficient substance to sustain continuing negotiations.

He repeated that the strike had cost the company tens of millions of euros and damaged customer confidence in the airline.

“The effects of this strike are very damaging,” he said, calling on the pilots' union to resume negotiations “within the next few days.”

In an unusual step for a German company, Lufthansa chief executive Christoph Franz appeared on a YouTube video just after the strike began to apologise in English for the stoppage, saying he wanted to “make the inconvenience as small as possible.”

Werner Knorr, a Lufthansa executive, said the airline would fly almost all its 1,800 scheduled flights Saturday despite the fact that many jets have been stranded away from the airports where they are needed. Mechanics would work overtime to get planes airborne quickly, he said.

The airline says very few passengers have been stranded at its two biggest hubs, Frankfurt and Munich, because most were either rebooked or cancelled travel.

The strike was announced in advance.

The pilots have also demanded a 10-per-cent wage increase over two years.

The airline has responded to the union's demands by offering a one-off plus a two-step increase of 5.16 per cent over five years.

A poll for ARD television on Thursday showed 55 per cent of Germans sympathise with the pilots, whereas 42 per cent think the strike is wrong. - Sapa-dpa