Built from 1972 to 1974, the tower is 179 m (587 ft) tall at roof height. However, it reaches 187 m (614 ft) once including the antenna located on the roof. It is the third-tallest skyscraper in La Défense after Tour Total and Tour Areva. Its ground shape is in the form of a Greek cross.
In 1972, during construction, a protest campaign opposed the building of Tour Gan, which was deemed too tall and thus too visible from the historical center of Paris and particularly from the Champs-Elysées. Protesters demanded a reduction in height. However, those protests had no effect and the tower was completed at the planned height.
All the asbestos from the Tour Gan was removed between 1995 and 2001.