OYAK (Ordu Yardımlaşma Kurumu) is the pension fund of the Turkish Armed Forces, with around 260,000 members in 2012. Its OYAK Holding investment subsidiary is one of the largest industrial groups in Turkey. It co-owns Oyak-Renault, a car manufacturer, and Erdemir, a steel producer, and is the former owner of Oyak Bank (sold to ING Bank in 2007) and the Oypa supermarket chain.