Key takeaways
No special treatment for amendments in counterclaims for revocation
The Rules of Procedure on amendments apply equally to counterclaims for revocation as to infringement actions; no leniency is afforded to counterclaimants.
All grounds for revocation and supporting documents must be included with the initial counterclaim.
Late-filed prior art faces strict scrutiny
New prior art can only be introduced if it could not have been found earlier with reasonable diligence.
Easily discoverable prior art, even if overlooked, is not a valid basis for late amendment.
Procedural certainty outweighs risk of separate revocation actions
The defendant's interest in a stable scope of invalidity attacks takes precedence over the claimant's interest in introducing new attacks late.
The need for fairness, equity, and procedural economy does not justify relaxing amendment requirements.
Division
Local Division Mannheim
UPC number
UPC_CFI_745/2024 (CCR: UPC_CFI_200/2025)
Type of proceedings
Infringement action with counterclaim for revocation
Parties
Sunstar Engineering Europe GmbH (Claimant in infringement action and Defendant in counterclaim for revocation)
Sunstar Engineering Inc. (Defendant in counterclaim for revocation)
vs.
CeraCon GmbH (Defendant in infringement action and Claimant in revocation action)
Patent
EP 4 108 413
Jurisdictions
UPC
Body of legislation / Rules
Rules 25(1)(b), (c), (d), 29, 263 RoP
The content of this article is intended to provide a general guide to the subject matter. Specialist advice should be sought about your specific circumstances.