Article L3132-4 of the French Public procurement code
When a public law granting authority has entered into a works concession contract or has awarded a concession for the management of a public service:1° The assets, whether movable or immovable, that result from investments made by the concessionaire and are necessary for the operation of the public service are returnable assets. Where the contract is silent, they are and remain the property of the public entity as soon as…