Gassco is a Norwegian state owned company that operates 8,800 kilometres (5,500 mi) of natural gas pipes and associated riser platforms and land-based facilities transporting annually of 100 billion cubic meter (bcm) of natural gas from the Norwegian continental shelf to Continental Europe and Great Britain.

15% of the total consumption of natural gas in Continental Europe is distributed through Gassco. The actual ownership is organised through various licences, with Gassled, being the largest. Gassled is owned by Petoro.

Gassco was founded by the Ministry of Petroleum and Energy (MPE) on 14 May 2001, and took over the operatorship of all gas transport from the Norwegian continental shelf on 1 January 2002. This activity had previously been carried out by several companies, and the creation of Gassco formed part of an extensive reorganisation of Norway's oil and gas sector in 2001. It complied with the requirements stipulated in the European Union's gas market directive for organising transport operations in this sector.

The political considerations which underpinned the creation of Gassco found expression in proposition no 36 (2000–01) to the Storting (parliament) and the subsequent recommendation from the Storting's standing committee on the environment. These documents specified in part that transport and processing plants must serve all gas producers, and that Gassco must act in a neutral manner towards these. The company was assigned a key role in the further development of the gas transport system, which would contribute to efficient overall utilisation of resources on the NCS. More about Gasscos history.

Gassco is the operator for the integrated system for transporting gas from the Norwegian continental shelf to other European countries. This role confers overall responsibility for running the infrastructure on behalf of the owners. Frame conditions for the company are determined by the Norwegian government. That also applies to the relationship between Gassco and the owners of the gas transport system. The company exercises its operator responsibility pursuant to the Norwegian Petroleum Activities Act and to agreements with the transport system owners.

As operator, Gassco plays several roles. The work it carries out on behalf of the transport system owners is usually designated the normal operatorship. The owners finance most of the major investments in the transport system and recognise this spending in their own accounts. Gassco's responsibility for system operation and capacity administration is usually referred to as the special operatorship. Directly authorised by the Petroleum Activities Act, this work is conducted for all users of the Norwegian gas transport system.

The cost of operating the transport system is met by its users through tariff payments. The capital element in these tariffs also covers investment made by the owners. Pursuant to the Petroleum Activities Act, Gassco additionally has the right and duty to pursue unified further development of the gas infrastructure. Gassco does not make a profit or a loss from its own operations.

Gassco operates three Norwegian gas processing plants, namely the Kårstø processing plant, the Kollsnes processing plant and the Nyhamna processing plant.