Most passengers traveling Friday on the German national carrier Lufthansa can expect their flights to be canceled.

With the flight attendants' union (UFO) calling for an all-day nationwide strike Friday, the airline has cancelled some 1,200 flights going into the weekend, or almost two-thirds of its planned connections. About 600 flights are supposed to leave on schedule. The cancellations are affecting several long-distance flights, with the company saying that most passengers have already been rebooked. But the airline's domestic and inner-European service will be brought to a virtual standstill.

More than 40 connections scheduled for Thursday have likewise been cancelled. The airline said the measure was taken so that it will be able to offer some flights once the strike comes to an end after Friday. There are concerns that other airlines could also be affected by the strike as happened a week ago when the Frankfurt airport briefly closed to European traffic due to a lack of space for incoming planes.

Lufthansa has posted information on its website in German and English , under "UFO Strike," informing travellers of the cancellations on Friday.  After the strike ends, the airline expects "irregularities" in its scheduled flights, according to the site. The site also has a list of phone numbers for further assistance as well as information on how to receive a voucher should passengers wish to travel by train instead.

The airline's board bought advertisements in major German papers Thursday in which it wrote: "We consider this strike to be excessive. It is inflicting large financial damages on the company and is hurting the reputation of the Lufthansa brand."

Year-Long Battle

Some 43,000 Lufthansa customers were affected on Tuesday, when the union held strikes in Berlin, Frankfurt, and Munich, forcing 350 flights to be cancelled. About 1,500 passengers were stranded overnight in Frankfurt and Munich, prompting the airline to set up cots to accommodate them. The first strike held last Friday at Frankfurt airport  caused the airline to cancel nearly half of the 360 flights scheduled to take off that morning.

The strike scheduled for this Friday, however, will be much larger, affecting all the airports in Germany served by Lufthansa. On a typical Friday, Lufthansa usually serves some 170,000 passengers.

Chances that a last-minute compromise between the airline and the union will be found are considered slim, since both sides have been battling over a collective wage agreement  for more than a year. On Friday, both sides indicated they were open to a resumption of talks, but said the other side needed to make the first move.

The union is demanding a 5 percent wage increase and profit-sharing for the cabin staff and chief flight attendants, or pursers. But the context includes the airline's plans for substantial cost-cutting measures, which would affect those staff members.