T 0891/16 - Grounds for opposition are not personal

Key points

• In this case, there are two opponents. Only opponent II raised Article 100(c) as ground of opposition in the first instance proceedings (namely in its Notice of opposition). Only Opponent I takes up this ground in appeal. Is this allowed or is this a 'fresh ground for opposition in appeal'  which is impermissible under G 10/91?
• The Board: "it is established case law that multiple admissible oppositions do not initiate a corresponding number of parallel opposition proceedings but only a single one and that each opponent can rely on an opposition ground duly submitted by other opponents [...] both in the opposition proceedings and in any subsequent appeal proceedings" (IV.C.2.1.6)

EPO T 0891/16 -   link

2.3.2 The proprietor requested to disregard the observations filed by opponent I on Article 100(c) EPC since opponent I introduced this ground of opposition for the first time with its statement of the grounds of appeal.

2.3.3 The Board observes that it is established case law that multiple admissible oppositions do not initiate a corresponding number of parallel opposition proceedings but only a single one and that each opponent can rely on an opposition ground duly submitted by other opponents and communicated to all parties in accordance with Rule 79(2) EPC respectively Rule 57(2) EPC 1973, both in the opposition proceedings and in any subsequent appeal proceedings, see Case Law of the Boards of Appeal, 9th Edition, 2019, IV.C.2.1.6. In the present case, the notice of opposition filed by opponent III was based, among others, on the ground of opposition under Article 100(c) EPC 1973, and in particular contained reasons why in its view Feature 5 contravened Article 123(2) EPC (see point 4 of the notice of opposition filed by opponent III).

Hence, the observations of opponent I with respect to the ground under Article 100(c) EPC 1973 are not to be disregarded, even if opponent I did not address this ground of opposition in the opposition proceedings.