GEK was founded in 1969 while TERNA was established three years later, in 1972. Both GEK's and TERNA’s shares were listed on the Athens Exchange in 1994. In 1999, GEK and TERNA joined forces, creating one of the largest Greek groups in the fields of construction, energy and real estate. In 2002, the construction sector of GEK was absorbed by TERNA. Finally, on 23 December 2008, GEK absorbed all the remaining activities of TERNA, becoming officially GEK TERNA.