The Spanish gas sector has remained within its characteristic expansive trend for some years. The number of clients increased by 4.7% to 6.78 million. The length of the network reached 63,199 km and the municipal districts with natural or manufactured gas services now total 1,325. The counterpart is the significant investment effort that is being made by the Spanish gas sector. In particular, in 2007, a total of €1,208 million were invested. Over the last 10 years, the material investment in natural gas infrastructures in Spain reached the figure of €9,344 million.

The legislation adopted in 2007 includes Act 12/2007, which modifies the Hydrocarbons Sector Act 34/1998 in order to adapt it to the provisions laid down in Directive 2003/55/CE of the European Parliament and Council on common standards for the domestic natural gas market. Similarly, Royal Decree 1068/2007, dated 27 July, which regulates the start-up of the last-resource supply in the natural gas sector. Clients who decided not to choose the offer of a marketer at an off-tariff price before that date will be supplied by a marketer at a cost set by a last-resource tariff. This tariff was published in the Official State Gazette (ORDER ITC/3861/2007, which lays down the last-resource tariff for the natural gas system for the year 2008) on 29 December 2007.