Lufthansa had to cancel 44 flights on Friday after trade union UFO called on flight attendants to stage a warning strike.

Several hundred passengers who had booked seats on domestic and European flights were affected by the cancellations and some delays, a spokeswoman for Lufthansa said.

UFO is pushing for better wages for cabin crew members and could call for further warning strikes in the near future, its head negotiator Joachim Mueller said.

Earlier this month, a third round of wage talks for 16,000 flight attendants failed. The union is calling for a wage and benefits rise of 15 percent.

Lufthansa has increased its offer to a rise of up to 10 percent, from 9.1 percent. The package includes better work conditions and profit sharing.

The German airline called on UFO at the time to return to the negotiating table and face up to "economic realities".

Last July, Lufthansa's passenger numbers were hurt as strikes by ground staff and cabin crew as well as walkouts by regional pilots forced the carrier to cut flights.

The wage agreement that ended that walkout adds about EUR100 million euros (USD$130 million) to costs every year, the company has said.

In addition, airlines have been hard hit by the escalating financial crisis, with passenger numbers dwindling. Lufthansa in October cut its 2008 operating profit goal to EUR1.1 billion, from a previous estimate of about EUR1.38 billion.