The TRANSITGAS PIPELINE is 293 kilometres long, has one compression station, and transports natural gas mostly from the Netherlands and from Norway. It crosses Switzerland for 165 kilometres  from Wallbach, where it joins the pipeline system owned by Trans Europa Naturgas Pipeline GmbH (TENP) , to Passo Gries at the Italian border where it joins the italian network owned by Snam Rete Gas S.p.A..

 In 2001 a new, 55-kilometre line from Rodersdorf/Oltingue (an interconnection point with the network owned by Gaz de France), at the French-Swiss border, to Lostorf (an interconnection point with the line coming from Wallbach) was built for transporting Norwegian gas.

The Transitgas pipeline came on stream in April 1974 and a massive expansion of the transport system occurred between 1998 and 2003.

Eni Gas Transport International SA and Swissgas AG have also entrusted Transitgas AG, owner of the pipeline, with running and maintaining the system.