"The Competition Commission has inflicted a sanction of 6.2 million francs ($6.7 million) on four international transit companies who fixed fees and surcharges in the area of air freight," the regulator said in a statement on Tuesday.

The commission, or Comco, said it had decided on December 11th to hand the biggest fine of 3.12 million francs to Swiss Panalpina Welttransport, while another Swiss company, Kuehne and Nagel, was fined 1.17 million francs.

The German national rail company Deutsche Bahn received a 1.02-million-franc fine, while the Kuwait-headquartered Agility Logistics International was fined 907,349 francs.

The German postal service Deutsche Post had also taken part in the cartel, but since it turned itself in and alerted the authorities to the illegal practices it was offered immunity, Comco said.

Deutsche Bahn and Agility had also negotiated and received lower fines, the regulator said.

Comco explained that it had launched the probe in October 2007, and determined that the companies in question had from 2003 to 2007 coordinated certain fees and surcharges for air freight passing through Switzerland.
  
"Such horizontal deals constitute serious offences," it said.