Article 54

1. In the event of an application for a declaration of invalidity of a registered Community design being filed, and as long as no final decision has been taken by the Office, any third party who proves that proceedings for infringement of the same design have been instituted against him may be joined as a party in the invalidity proceedings on request submitted within three months of the date on which the infringement proceedings were instituted. The same shall apply in respect of any third party who proves both that the right holderof the Community design has requested that he cease an alleged infringement of the design and that he has instituted proceedings for a court ruling that he is not infringing the Community design.

2. The request to be joined as a party shall be filed in a written reasoned statement. It shall not be deemed to have been filed until the invalidity fee, referred to in Article 52(2), has been paid. Thereafter the request shall, subject to any exceptions laid down in the implementing regulation, be treated as an application for a declaration of invalidity.