CDC Arkhinéo is a 100% subsiduary of Caisse des Dépôts.
Caisse des Dépôts group is a "Public Group serving general interest and economic development".
Created in 1816 to restore confidence following the financial crisis after the Napoleonic wars, its first task is to "receive, conserve and return the values entrusted to it". From there onwards, its missions have kept growing to correspond to the country's pressing issues.
To know more about Caisse des Dépôts : http://www.caissedesdepots.fr/en/home.html
To know more about Caisse des Dépôts subsiduaries : http://www.caissedesdepots.fr/en/the-group/organisation/subsidiary-companies.html