The EPO's Board of Appeal has clarified the position with respect to the applicant's right to claim priority in recently published decision T 577/11.

The case concerns an appeal by the patent proprietor against the revocation of their European Patent No. 1540227. The patent in question was based on the European regional phase application of International Patent Application PCT/EP2003/009870 filed on 6 September 2003 in the name of Tenaris Connections AG, a Dutch corporation.

Significantly, however, the International application claimed priority from Italian Patent Application No. RM2002A000445 filed in the name of Tenaris Connections BV, a Liechtenstein corporation.

A patent assignment agreement between Tenaris Connections AG and Tenaris Connections BV was executed on 9 September 2003 – some three days after the end of the Paris Convention deadline – and included a clause giving retrospective effect to the assignment back to the beginning of January that year.

During the preceding opposition proceedings, the EPO's Opposition Division took the view that priority had been validly claimed, since the assignment agreement proved that the transfer of rights, including priority rights, took place with effect from 1 January 2003, and thus before the filing date of the International application.

In contrast, the Appeal Board's provisional opinion was that, although the assignment agreement including its retroactive effect might be a valid agreement under national law, this could not overcome the fact that it had been concluded after the filing date of the European patent application, with the result that the priority claim was invalid.

During the appeal proceedings, the patent proprietor argued, amongst other things, that:
There was no requirement in Article 87(1) EPC that the subsequent applicant had to be the successor in title when the subsequent application was filed, the 12-month period being relevant only for the filing of the subsequent application;

  1. Based on Italian national law, the rights mentioned in the assignment agreement were validly transferred with effect from 1 January 2003 since Article 1322 of the Italian Civil Code provides for retroactivity clauses;
  2. Based on Italian national law, the filing of the International application by Tenaris Connections AG evidenced that the right to claim priority has been transferred, since Italian law provides that a contract may be entered into "by carrying out convincing behaviour" within a corporate group; and
  3. Based on Dutch national law, while the assignment agreement transferred – with retroactive effect – the economic ownership (economische eigendom) and not the legal ownership of the patent application, this was still sufficient under Dutch national law to make Tenaris Connections AG the successor in title for the purposes of Article 87(1) EPC 1973 (NJ 2007, 155).

The Board, in its reasons accompanying the decision, first established that the EPC is applicable, since an international application is deemed to be a European patent application as of its international filing date (Article 150(3) EPC 1973 and Article 11(3) PCT). Moreover, the PCT explicitly accords primacy to "national law" – which the Board concluded to be the EPC for European regional applications or patents – such that Article 87(1) EPC 1973 (and not Article 8 PCT or Article 4 Paris Convention) must be applied.

Regarding the patent proprietor's arguments, the Board held that:

  1. A time constraint as to the question of succession in title is imposed by Article 87(1) EPC 1973. The requirement that the succession in title must have occurred when the subsequent application is filed is clearly derivable from the wording "has... filed" and "shall enjoy, for the purpose of filing a European patent application" of Article 87(1) EPC 1973.
  2. The retroactive effect of the assignment agreement had not been sufficiently well established by the patent proprietor, such that the Board was unable to satisfactorily conclude that Tenaris Connections AG was the successor in title according to Italian law.
  3. While the Board accepted the patent proprietor's argument that, under Italian law, patent applications and priority rights may be transferred "by carrying out convincing behaviour", the Board's view was such a transfer had not been proven. In the Board's view, the act of filing a subsequent application of one company of a corporate group which claims priority from an earlier application of another company of the same corporate group does not clearly imply that there was a mutual agreement between the companies concerning a transfer of ownership of the priority application or the priority right arising from it, the Board pointing to the text of the assignment agreement "hereby assigns and transfers" as evidence that an ordinary reader would not assume that a transfer of the rights had already occurred prior to its conclusion.
  4. While the Board accepted that economic ownership exists as a legal concept under Dutch law, the Board was not satisfied that the transfer of economic ownership as opposed to legal ownership qualifies as a "succession in title" according to Article 87(1) EPC 1973, noting that "economische eigendom" can be distinguished from "ownership in equity" referred to by the patent proprietor when citing earlier decision J 19/87.

The Board thus concluded that transfer of ownership of the priority application and the right to claim priority from it was too late, and the patent was subsequently revoked due to lack of an inventive step.

This decision clarifies that the burden of proof on establishing the right to claim priority rests with the applicant, and that the appropriate chain of title must be clearly established in order to ensure the correct applicant (or applicants) is (or are) identified at the time priority is claimed.

The Board noted, for example, that where it has not been possible to execute an agreement within the priority year, the subsequent application could be filed by the entitled person and be assigned, together with the other rights, afterwards. Alternatively, both the original applicant and the successor in title-to-be could file the subsequent application jointly.
The Board also noted that the absence of a need to file proof of entitlement cannot automatically lead to the conclusion that the applicant need not be entitled to the right at a particular point in time.

Notably also, the Board avoided having to decide which national law is applicable for assessing the validity of the transfer of the priority application or the priority right or whether, or under what conditions, the priority application and the priority right are transferable under the relevant law, since in the Board's view none of the proprietor's lines of argument, which were based on the applicability of Italian and Dutch law, were successful and no other national laws were invoked by either of the parties.

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