Lufthansa has threatened to close its fleet of freighter aircraft if restrictions on night flights are imposed on its hub at Frankfurt. Carsten Spohr, the CEO of Lufthansa Cargo was quoted by Reuter’s last week as saying that it might no longer pay to have its own cargo fleet.

“Everything that goes toward a single-digit number (of flights allowed per night) would mean that it no longer pays off to have our own cargo fleet,” he said according to the report.

His comments come after a recent court ruling that avoided determining whether night flights should be banned at Frankfurt airport, Germany’s largest, to limit noise pollution after the airport adds another runway in 2011, instead deferring the decision to the politicians.

The German state of Hesse, home to Frankfurt, approved in 2007 plans to expand the airport, but one condition was that flight movements were limited to an average of 17 per night between 11 pm and 5 am local time to cut down on noise.

Lufthansa said when court proceedings began in June it alone would require an average of 23 flights a night by 2020 for passenger and cargo flights. Requirements by tour operators such as Thomas Cook’s Condor would come on top of that.

In the worst case, Lufthansa Cargo could gradually shrink its fleet from currently 19 planes, Spohr said. About half of Lufthansa cargo travels in those planes, while the other half is transported in the cargo hold of its passenger planes.

Shifting the company’s operations to another city, such as the eastern German city of Leipzig, was out of the question, Spohr told Reuters.