55. The expropriating party may, with the authorization of the tribunal, totally or partially discontinue his suit at any time before payment of the provisional indemnity of expropriation. The order of the tribunal to that effect must be registered by deposit in the registry office where the notice of expropriation had been registered. Subject to the registration of that order, the discontinuance is retroactive from the date of registration of the notice of expropriation.
In the case of partial discontinuance, the tribunal shall fix the amount of the indemnity to which the expropriated party is entitled by taking the discontinuance into account and grant damages, if need be, for the portion of which the expropriating party has discontinued his suit.