CeraCon v Sunstar Engineering (CFI, 6 June 2025)

Date	6 June 2025
Court	CFI
Division	Mannheim (DE) Local Division
Type of action	Amend Document
Registry reference	App_22065/2025 · ORD_22156/2025
Parties	CeraCon GmbH

Official decision (PDF) · UPC registry entry

Dhenne Avocats represents claimants and defendants in European patent disputes before the Unified Patent Court, including the Paris divisions.

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Dhenne Avocats · 10 October 2026

Our analysis

Summary

The judge rapporteur of the Mannheim Local Division refused CeraCon leave to add to its counterclaim for revocation of EP 4 108 413 a lack of novelty attack based on prior art found later (EP 3 868 480). A counterclaimant enjoys no more favourable treatment under Rule 263 than an infringement claimant. The order is a reminder that the invalidity case must be complete when the counterclaim is lodged.

Question

May a counterclaimant for revocation obtain leave under Rule 263 to add a new prior art document two months after filing, on the strength of a supplementary search report?

Decision

Rule 263 applies in full to a counterclaim for revocation. Rule 29(e) does not suggest otherwise, and Rule 25.1(b) to (d) requires the grounds and evidence to be filed with the counterclaim.

Leaving open both negligence (Rule 263.2(a)) and unreasonable hindrance (Rule 263.2(b)), the judge balanced the interests: the patentee’s interest in not facing a late attack based on a document a reasonable search would have found prevailed. The application was dismissed.

Key points for practice

The prior art search must be finished before the counterclaim is filed: a later search report does not by itself justify adding a new attack.
The court may refuse leave on a balance of interests alone, without ruling on the Rule 263.2 criteria.

Provisions applied

Rules of Procedure: Rules 25.1, 29(e) and 263
Case law cited: Grundfos v Hefei Xinhu Canned Motor Pump, Düsseldorf Local Division, 8 May 2025, Mannheim Local Division, 14 May 2025, UPC_CFI_132/2024

Related decisions

Sunstar Engineering Europe v CeraCon, 6 June 2025, order of the same day on the damages request.

Prepared by Dhenne Avocats from the official decision, consulted on 10 October 2026. The database is updated every week, on Friday. Only the official text is authoritative.

Going further

Lexicon: Written procedure (UPC), Court fees and costs (UPC).

Source and translations

Official source: Unified Patent Court registry link recorded in the record
Original language: not recorded
Translation available: no translation recorded the firm’s French record is a summary, not a translation
Date checked: not recorded

Only the official text is authoritative. A machine translation is never presented as official, republishing a third-party document requires a verified basis in rights, and a link to the source is preferred.

Follow this case

Proceedings, related decisions, appeals, parties and patents as recorded in the registry and in the Dhenne Avocats corpus. Each link states its source.

Proceedings

No case number recorded in this record.

Parties

claimantCeraCon GmbH3 decisions in the corpus Follow this party

Exact name as it appears in the record, group affiliation only where sourced and dated.

Decisions in the same proceedings and documented appeals

No other decision in the corpus bears the same case number, and no appeal is documented in the corpus to date.

What the record states

Nature of the act: Amend Document
Outcome (Dhenne Avocats summary): La règle 263 s'applique pleinement à la demande reconventionnelle en nullité. L'ajout tardif d'une antériorité qu'une recherche raisonnable aurait révélée est refusé au terme d'une mise en balance des intérêts.
Appeal: No appeal documented in the corpus, this does not mean that no appeal was lodged.
Instance: First-instance decision, whether it has become final is not recorded.

Patents mentioned

EP 4 108 413 mentioned in: Dhenne Avocats analysis Follow this patent
EP 3 868 480 mentioned in: Dhenne Avocats analysis Follow this patent

Related decisions cited in the analyses

Sunstar Engineering Europe v CeraCon (CFI, 6 June 2025) cited in this record
Grundfos v Hefei Xinhu Canned Motor Pump (CFI, 8 May 2025) cited in this record
CeraCon v Sunstar Engineering (CoA, 2 September 2025) cites this decision

Scope: Dhenne Avocats corpus. Registry-based links are marked “official number”; links derived from the analyses are marked as such. An erroneous link can be withdrawn without deleting any record.

Patents and standards

Publication	Role in the dispute	Family	Standard and declaration	Pool	Sources
`EP 4 108 413`	Mentioned in the analysis (role not qualified) Also mentioned in 4 other decision(s): CeraCon v Sunstar Engineering (CoA, 2 September 2025) · Sunstar Engineering Europe v CeraCon (CFI, 8 August 2025) · Sunstar Engineering Europe v CeraCon (CFI, 6 June 2025) · Sunstar Engineering Europe v CeraCon (CFI, 30 May 2025)	not recorded	not recorded	not recorded	Espacenet links not checked mentioned in: Dhenne Avocats analysis
`EP 3 868 480`	Mentioned in the analysis (role not qualified) Also mentioned in 2 other decision(s): CeraCon v Sunstar Engineering (CoA, 2 September 2025) · Sunstar Engineering Europe v CeraCon (CFI, 8 August 2025)	not recorded	not recorded	not recorded	Espacenet links not checked mentioned in: Dhenne Avocats analysis

The statuses “asserted in litigation”, “declared essential”, “listed by a pool” and “essentiality examined by a court” are distinct and may coexist. Validity, infringement and technical essentiality are different questions. Scope: patents cited in the decisions of the Dhenne Avocats corpus, with no essentiality score or prediction.

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