Lufthansa's cargo division is considering several alternatives to Frankfurt as its main base in the event of a ban on night flights at mainland Europe's biggest passenger and freight hub.

Lufthansa Cargo is weighing up options both in Germany and in other European countries, said company spokesman Nils Haupt on Monday, denying media reports that it favored a move to Leipzig.

Frankfurt Airport operator Fraport has applied for a night flight ban between 11pm and 5am linked to the construction of a new runway planned for 2009.

The ban was considered a condition for the expansion by the government of the surrounding state of Hessen, which owns about a third of Fraport.

"We are looking for alternatives to Frankfurt. A night flight ban would endanger our existence," said Haupt. But he added that Lufthansa Cargo would prefer to remain in Frankfurt, where it employs 3,500 people, and hoped for a compromise.

"Frankfurt is our favorite place. We want to stay here," he said.

Lufthansa Cargo will have a presence in Leipzig in any event because its biggest customer, postal giant Deutsche Post's DHL express courier unit, is setting up a new European intercontinental hub there, Haupt said.

But no decision has been made on an alternative base to Frankfurt for Lufthansa Cargo, which is Fraport's biggest air freight customer.