Norwegian politicians expressed disappointment Tuesday over a ruling by an international court that Norwegian legislation on hydropower concessions violated European Economic Area rules, REPORTED DPA.. Norway is a member of the European Free Trade Association (EFTA) tha has signed the European Economic Area (EEA) treaty that links EFTA states to the European internal market. In its ruling Tuesday, the Luxembourg-based EFTA Court said Norway's system that allows public owners of hydropower plants to own concessions for "unlimited time" discriminated against private owners or prospective foreign buyers that were only allowed concessions of up to 60 years. The concessions then revert to the state that does not have to pay compensation. The court also disgreed with the Norwegian argument that state ownership was important from an environmental point of view. The legal process began in 2001. Petroleum and Energy Minister Odd Roger Enoksen said in a statement that he was "very disappointed" over the ruling, saying the "public ownership and control has been key in Norwegian hydropower administration since 1909 the concession legislation was introduced." Both Enoksen and Prime Minister Jens Stoltenberg said Oslo would study the ruling and its implications. Hydropower accounts for almost all of Norway's electricity production. The court documents said approximately 88 per cent of the total hydropower production capacity was in public ownership, almost half of that through the state-owned company Statkraft AS while municipalities and counties owned more than 42 per cent.