FRANKFURT, July 31, 2008 (AFP) - German national carrier Lufthansa planned to cancel 128 flights Thursday on the fourth day of a strike by maintenance and catering staff demanding a sizeable pay hike, a spokeswoman said.

The airline was forced to axe 100 German and 28 long-haul flights. It has prepared a provisional schedule through Monday that will ensure that 90 percent of scheduled flights can take off, she said.

Service-sector union Verdi launched the strike Monday in the peak holiday period to agitate for a 9.8-percent pay rise over a year for 50,000 employees.

Lufthansa, which has a healthy profit forecast for this year despite a shaky economy and the skyrocketing cost of fuel, has offered a 6.7-percent increase over 21 months.