Civil Code (Cap. 16), article 996

996. (1) Nevertheless, with regard t o third parties any contract conveying the ownership of immovable property, or any right ove r such property, shall, in no case, commence to be operative unti l it has been registered in the Office of the Public Registry, as pr ovided in article 330. (2) Where the alienation is made by judicial auction the note for the registration shall be signed by the registrar of the co urt under the authority of which the adjudication of the thing shal l have taken place. Where a movable thing is promised, by successive agreements, to two or more persons.