Mytilineos Holdings S.A., through its subsidiaries, engages in metallurgy, engineering, procurement, construction, and energy businesses in Greece and internationally. It is involved in the engineering, procurement, and construction of energy projects that use gas-fired combined cycle technology, as well as defense and infrastructure projects.it operates as an independent electricity producer with 1,200 megawatts from thermal plants, and approximately 130 megawatts from renewable energy sources projects, supplies electrical power to businesses, professionals, and households, and sources, trades in, and markets natural gas.