The building houses the head office of Fortum, an energy company owned primarily by the Finnish state. It was constructed between 1973 and 1978, while Uolevi Raade was the manager of Neste, which merged and later demerged with Imatran Voima, the predecessor of Fortum. This is why the building is sometimes referred to as Raaden hammas ('Raade's tooth'). When Imatran Voima merged with Neste, the merged company Fortum took the building as its HQ. However, in the demerger six years later, the building was not returned to Neste Oil, but was retained by Fortum, the electricity producer. Consequently Neste Oil had to construct a new HQ building nearby.