Gek Terna S.A., together with its subsidiaries, engages in the construction, energy, industry, real estate, and concession businesses in Greece, the Balkans, the Middle East, Eastern Europe, North America, and internationally. The company operates through Constructions; Electricity from Thermal Energy and HP Trading; Real Estate; Mining/Industry; and Concessions segments. It involves in the construction of public and private projects, including motorways and railway networks, building, hospitals, museums, industrial facilities, hydroelectric projects, dams, power plants, etc.; construction and operation of infrastructure, such as motorways, airports, parking stations, unified automatic collection system, and municipal waste treatment plant. The company also produces electric energy through fuels and natural gas, as well as trades in electric energy and natural gas. In addition, it acquires, develops, and exploits real estate; produces quarry products; and exploits magnesite quarries. Gek Terna S.A. was formerly known as Ermis Real Estate Constructions Enterprises S.A. The company was founded in 1960 and is headquartered in Athens, Greece.