The first phase of construction of the internal market for natural gas dates back to the nineties, namely to Directive 90/377/EEC of the 29th of June, which establishes a community process to ensure transparency in prices for industrial gas and electricity consumers, with the objective of promoting the free choice of supplier by these consumers, and Directive 91/296/EEC of the 31st of May relating to the transport of natural gas in large networks, which was aimed at facilitating increased trade, taking into account the quality and security of the supply.
In the second phase, Directive 98/30/EC of the 22th of June related to common rules for the natural gas market was approved. With this directive, Portugal has benefitted from a derogation to be recognised as an emerging market, meaning, "... a Member-State where the first commercial supply in the scope of its first long term natural gas supply contract was carried out less than 10 years ago”.
With this derogation, Decree-Law No. 14/2001 of the 27th of January established that the provisions relating to access to networks and storage, the eligibility of customers (opening of the market) and the refusal of access to the network or storage only came into force when the domestic market was no longer emerging, in 2007 at the latest.
In June 2003, Directive 2003/55/EC of the 26th of June which establishes common rules for the internal natural gas market and revokes Directive 98/30/EC was approved.
This directive accelerated the opening of the natural gas market, offering clients the right to choose their supplier, starting on the 1st of July 2007 at the latest, defining, with greater precision, the organisation and operating of the sector and the conditions to access the market, as well as the attributions and roles of independent regulatory bodies.
The principles of the directive were transposed to Portuguese national law by means of the Decree-Law no. 30/2006, of the 15th of February.
On the 22nd of June 2006, the Council of Ministers approved a bill related to the gas sector which, in terms of the liberalisation of the sector, establishes the following calendar:
- Electricity producers under an ordinary regime - January 2007;
- Clients with annual consumption greater than 1 million m3 (n) - January 2008;
- Clients with annual consumption greater than 10,000 m3 (n) - January 2009;
- For all clients - January 2010.