GEK Terna SA engages in the development and management of investment property, construction of any kind, the management of self-financed or co-financed projects, the construction and, operation of energy projects. It operates through following segments: Construction; Electric Energy Generation from Renewable Energy Sources (RES), Electricity Generation from Thermal Energy Sources and Sale of Energy, Concession, Real Estate, and Quarry and Industry. The Construction segment engages in the construction of technical projects. The RES segments focuses on the electricity production from wind generators, hydroelectric projects and other renewable energy sources. The Electricity from Thermal Energy Sources and Sale of Energy segment engages in the electricity production using natural gas as fuel, and trading of electric energy. The Concessions segment deals with the construction and operation of infrastructure and other facilities. The Real Estate Development segment is involved in the purchase, development and management of real estate. The Quarry and Industry segment concentrates in the production of quarry products and the exploitation of magnesite quarries. The company was founded by Nikolaos Kampas in 1959 and is headquartered in Athens, Greece.