In accordance with the Natural Gas Sector Commercial Relations Regulations (RRCGN), the Transmission System Operator is the RNTGN concessionaire, responsible in a specific area, for the development, operation and maintenance of the transmission network and its interconnections with other networks, when applicable, as well as for ensuring the long-term capability of the system to meet reasonable demands for the transport of natural gas.

Natural Gas Transmission System Operator in Portugal: