Key takeaways
An intervenor cannot contradict the party they support
The Court confirms that an intervenor must not act in contradiction to the supported party’s procedural acts or declarations. Consequently, the intervenor cannot oppose that party’s withdrawal of the appeal.
The intervenor has no independent appellate standing
Procedural steps by an intervenor are permissible only insofar as they support the principal party’s requests. The intervenor does not hold an autonomous procedural position. If the supported party exits the proceedings – in the present case through an appeal withdrawal following a settlement – the intervenor’s participation becomes inadmissible. Even where both filed appeals, the appeal constitutes a single remedy that cannot be continued independently; the intervenor’s appeal therefore becomes moot under Rule 360 RoP.
Limited binding effect where the intervenor was prevented from pursuing the appeal
Although decisions normally bind the intervenor (Rule 316.3 RoP), this effect is restricted when the intervenor was prevented from obtaining appellate review because the main party withdrew. In future proceedings, the intervenor may argue that the first-instance judgment would have been overturned.
Costs follow the treatment of the principal party
Intervenors are generally treated like the supported party with respect to costs. Since the principal party placed itself in the position of the losing party by withdrawing its appeal, the intervenor must bear its own costs.
Division
CoA Luxembourg
UPC number
UPC_CoA_70/2025 and UPC_CoA_001/2025
Type of proceedings
Decision concerning the admissibility of a party’s withdrawal of the appeal pursuant to Rule 265 RoP and the mootness of the intervener’s appeal.
Parties
Appellant and Defendant in the main proceedings:
STRABAG Infrastructure & Safety Solutions GmbH
Respondent in the appeal and claimant in the main proceedings:
SWARCO FUTURIT Verkehrssignalsysteme GmbH
Patent(s)
EP 2 643 717
Body of legislation / Rules
Rule 265 RoP, Rule 313 RoP, Rule 316 RoP, Rule 360 RoP
Art. 79 UPCA

