c) Filing of new dependent or independent claims 

(i) Filing of new dependent claims (sub-claims)

As explained in T 829/93 and T 317/90, the addition of a dependent claim is not a response to an objection that the claimed subject-matter is not patentable because it neither limits nor amends the subject-matter claimed in the relevant independent claim. The fact that dependent claims can serve as an important safety net should the corresponding independent claim ultimately be refused does not render it legitimate to add them to a remaining, broader independent claim in opposition proceedings. See also T 313/98, which cited T 829/93 in the context of R. 57a EPC 1973.

In T 340/10, the board reiterated that, in accordance with R. 80 EPC and the boards' settled case law, amendments to the text of a granted patent during opposition proceedings were considered appropriate and necessary, and so admissible, only if they were aimed at overcoming a ground for opposition under Art. 100 EPC (see e.g. T 317/90, T 794/94, T 674/96). In line with earlier case law, it explained that adding dependent claims was not, however, an answer to an objection that the claimed subject-matter was not patentable, because they neither limited nor amended the subject-matter of the related independent claim and so had no effect on its scope. It therefore considered the amendments to contravene R. 80 EPC.

(ii) Filing new independent claims

In T 610/95 the board referred to G 1/84 (OJ 1985, 299), which made it clear that the opposition procedure was not designed to be an extension of the examination procedure. It would, in the board's opinion, contravene the principles set out in G 1/84 if it was considered admissible to amend the text of a granted patent during opposition proceedings, while maintaining the sole independent claim under opposition, by incorporating an additional new independent claim which as such had no counterpart in the granted patent. See also T 2063/15 (summarised below).

In T 223/97 the board confirmed that the addition during opposition proceedings of one or more independent claims while maintaining the main claim in question could not be considered to be a restriction to the main claim in order to meet the ground for opposition raised against it. However, the replacement of one independent claim as granted by several, for example two, independent claims each directed to a respective specific embodiment covered by the independent claim as granted was admissible if the replacement was occasioned by grounds for opposition. See also T 428/12.

Referring to the above decisions, the board held in T 181/02 that only in exceptional cases could the replacement of a granted single independent claim by two or more independent claims be occasioned by a ground for opposition, for example where a granted independent claim covered two specific embodiments. Such a situation might also arise if two granted dependent claims (e.g. claims 2 and 3) were linked in parallel to a single independent claim (claim 1). Then the filing of two independent claims (e.g. including the features of claims 1 and 2, and 1 and 3) might be possible (moreover thereby decreasing the number of claims). However, it was normally sufficient for the patentee to remain with a single independent claim solely by modifying the granted claim once, i.e. by adding one or more features to the granted single independent claim. See also T 1689/12; see further T 1810/14, where the board defined a further situation in which the replacement of a granted sole independent claim by two independent claims may be admissible.

Citing the above case law, the board in T 263/05 (OJ 2008, 329) added that, when examining the amendments, it did not have to decide whether the ground for opposition would occasion the replacement of a granted single independent claim by two or more independent claims only in "exceptional cases". Rather, it had to be asked in each individual case whether the proposed amendments were an appropriate and necessary response designed to avoid revocation of the patent and could thus be regarded as occasioned by the grounds for opposition. See also T 428/12 and T 2063/15 (summarised below).

In T 937/00 the board saw no objection in principle to a patentee amending its claims in response to an opposition so that they comprise several independent claims directed to different subject-matters originally covered by a single generic claim of a given category, when such claim cannot be maintained. However, the board noted that the filing of multiple independent claims directed to different inventions might unduly complicate and delay the opposition procedure, in particular when this filing was followed by a series of further amendments. An efficient and possibly complete examination of the opposition might for instance become virtually impossible if subsequent amendments were proposed in a piecemeal way rather than addressing all the objections raised by the other party as soon as these objections arose. See also T 2290/12, in which the board considered it legitimate to seek to cover parts of an initially granted claim later found by the opposition division to lack inventive step by including them in a series of independent claims so long as this did not amount to an abuse of procedure and the number of independent claims was not unreasonably high.

In T 1/05 the board did not regard the introduction of product-by-process claims as an amendment occasioned by a ground for opposition. The submission of such claims demonstrated that these amendments were not directed to addressing a ground for opposition but were intended to compensate for the effects of an amendment that had been made to address such a ground, namely deletion of the product claims.

In T 2063/15 the request at issue comprised two independent claims. However, whilst claim 2 was based on a combination of claims 1 and 9 as granted, claim 1 was based on a combination of claims 1 and 2 as granted and also additional features taken from the description. The board explained that, with the subject-matter of claim 1 as granted having been found not to be novel, one or more independent claims based on a combination of claim 1 as granted with features of granted claims dependent upon claim 1 could be understood to be occasioned by the ground for opposition under Art. 100(a) EPC. However, with reference to G 1/84 (OJ 1985, 299), T 610/95 and T 223/97, the board held that the inclusion of the additional independent claim 1 was no longer simply occasioned by a ground for opposition, since this ground was already addressed through the filing of independent claim 2; the additional independent claim 1 furthermore introduced claimed subject-matter which had no counterpart in the claims of the granted patent.

Likewise in T 1764/17 the board emphasised that the replacement of a granted single independent claim by two or more independent claims could only in exceptional cases be considered to be occasioned by a ground for opposition. An exception could arise if two granted dependent claims were linked in parallel to a single independent claim. Then the filing of two independent claims including each one of the two parallel claim combinations might be possible, thus allowing separate fragments of the scope of protection afforded by the patent as granted to be retained. However, this exception did not apply to the addition of an independent claim directed at an aspect of the invention that was not included in the granted set of claims. In the case in hand, at least one of the two independent claims was directed at subject-matter that incorporated new features extracted from the description, which could moreover be material for the issue of patentability. These independent claims were thus not straight combinations of granted claims and the above exception did not apply.