Third party  proceedings constitute an extraordinary appeal intended to cause a judgment to be withdrawn or overturned in favor of the third party (Code of Civil Procedure [CPC], Art. 582). Any person who has an standing to bringing third party proceedings is entitled to file an application provided that it was neither a party to nor represented in the contested ruling   (CPC, Art. 583). Any judgment is subject to third party proceedings unless the law provides otherwise (CPC, Art. 585).

A third party may file an appeal against a decision rendered by the Paris Court of Appeals pursuant to Articles L. 464-1, L. 464-7 or L. 464-8 of the Commercial Code. The rules of ordinary procedural law apply in competition disputes, provided that they are not incompatible with the provisions of Title IV of Book IV of the Commercial Code, which do not expressly exclude them. Even if it rules on a decision handed down by the Competition Authority, which is an administrative body, decisions of the Paris Court of Appeals are judgments within the meaning of Article 585 of the CPC. The opponent’s standing as a third party requires it to be neither a party to nor represented by any of the parties to the original proceedings and must cite an interest in bringing the proceedings which is distinct from that of any of the parties.