FRANKFURT, August 8, 2008 (AFP) - More than 100 flights by Lufthansa's regional unit Cityline were cancelled on Friday because of a pilot's strike.

In light of 'clear warning signs' in the air transport sector, Lufthansa boss Wolfgang Mayrhuber said the pilots were cutting off 'the branch they are sitting on.'

Mayrhuber told the regional daily Neue Osnabruecker Zeitung that the strike could threaten jobs as it would hurt Lufthansa's ability to compete against other carriers.

He also said Cityline pilots already earned 'between 20-25 percent more than regional transport colleagues.'

The pilots want their pay to be raised to the level of Lufthansa counterparts, and after rejecting a proposed 5.5 percent increase, the Cockpit trade union called for new walkouts.

On Friday, around 140 flights were cancelled, but the day before 360 regional or European flights were grounded, roughly 90 percent of the airline's service.

Lufthansa has just reached an accord with ground personnel and cabin crews that ended strikes last week.