If a third party provides proof, e.g. a certificate from the court concerned, to the EPO during opposition proceedings or during the opposition period that he has opened proceedings against the proprietor of the European patent for the purpose of seeking a judgment that he is entitled to the European patent, the Opposition Division must stay the opposition proceedings unless the third party consents to their continuation. Such consent must be communicated in writing to the EPO and is irrevocable. However, stay of the proceedings may not be ordered until the Opposition Division has deemed the opposition admissible. The parties are to be informed of the order staying the proceedings.