Filing a Divisional Application in Europe: A Risky Endeavor?

A patent grants an inventor rights for a single invention, but occasionally a patent may be sought for a claim that involves more than one invention. In such a situation, the inventor may be required to file a "divisional application," which grants rights on a pertinent part of the original invention. Furthermore, in cases where the allowability of some claims is more strongly disputed by the Examining Divisions than others, the applicant may decide to prosecute the more controversial claims in a divisional application and to seek an allowance for the less contended ones.

The prerequisites for filing divisional applications and the principles of their generation are stipulated by Article 76 of the European Patent Convention ("EPC"). The filing procedure is very similar to that for the parent application, but the divisional application "may be filed only in respect of subject matter which does not extend beyond the content of the earlier application as filed; in so far as this provision is complied with, the divisional application shall be deemed to have been filed on the date of filing of the earlier application and shall have the benefit of any right to priority."

(See Art. 76(1) EPC.) The interpretation of this stipulation has been clarified by a decade of case law unchallenged until two recent decisions.

The following considerations summarize the present situation and seek to define the best way to cope with it.

Last September, a Technical Board of Appeal ("BoA") dissenting from established case law referred several questions to the Enlarged Board of Appeal for a final decision in Case G1/05 (see T39/03, as yet unpublished in the Official Journal, but see also http://legal.european-patent-office.org/dg3/biblio/ t030039ex1.htm). The questions raised in the application are as follows:

1. Can a divisional application which does not meet the requirements of Article 76(1) EPC because, at its actual filing date, it extends beyond the content of the earlier application, be amended later in order to make it a valid divisional application?
2. If the answer to question (1) is yes, is this still possible when the earlier application is no longer pending?
3. If the answer to question (2) is yes, are there any further limitations of substance to this possibility beyond those imposed by Articles 76(1) and 123(2) EPC? Can the corrected divisional application in particular be directed to aspects of the earlier application not encompassed by those to which the divisional as filed had been directed?

Question (1) refers to the practice of the European Patent Office ("EPO") of allowing the applicant to remove subject matter added to the disclosure content of the parent application for a retroactive remedy of the mentioned requirements. This practice was specified in the Examination Guidelines, Chapter VI, 9.1.4, and was approved by the Technical Boards of Appeal in a number of decisions; see for instance T1074/97 or T1092/04.

The dissenting Board holds the view that this practice does not comply with the literal meaning of Article 76 EPC. Furthermore, Rule 25(1) EPC, said to preclude the more liberal approach of that former practice, requires a divisional application to be filed while the corresponding parent application is still pending, i.e., until the day before notice of the grant of the parent application is published in the European Patent Bulletin. Removing the added subject matter, as was customary in the former practice, would result in the validation, or "resurrection," of an ineffective divisional application, and the dissenting Board considered the amendment practice in the divisional case comparable to the filing of a new divisional application. However, because filing a divisional application would no longer be possible in view of Rule 25(1) EPC if a patent for the parent case had already been granted, the dissenting BoA concluded that the amendment practice is contrary to Rule 25 EPC.

Recognition of the need to rethink case law was probably triggered by problems in relation to second-generation (or "grandchild") divisional applications, i.e., divisional applications that stem from an application that is itself a (first generation) divisional application (or "child") of an older, parent application. A decision by the same BoA, T1158/01 (see OJ EPO 2005, 110), held that: "When assessing the validity of a divisional application of second generation, also the validity of the divisional application of first generation from which it stems has to be assessed. In cases where the subject-matter of the divisional application of first generation does not fulfill the requirements of Art. 76(1) EPC, the divisional application of second generation is also invalid."

Thus, assessing the validity of a second-generation (grandchild) divisional application requires more than a comparison of the disclosure content of all its ancestors. It also depends on how the first-generation (child) divisional application is prosecuted. For instance, if subject matter is added during prosecution and remained (undetected) in the granted child application, the grandchild application as well as any further generation divisional application is null and void. Consequently, the validity of a grandchild application cannot be determined as long as the child application is still pending before the EPO in examination since it cannot, for example, be ruled out that in the course of examination of the child application, an inadmissible broadening occurs. The dissenting Board concludes that the "inconvenience of such practice in terms of legal certainty for the public is evident" and that this "could be avoided if the validity of the first generation (child) divisional application under Art. 76(1) EPC was only to be judged once, on the sole basis of its version as originally filed."

Question (2) to the Enlarged Board of Appeal aims at the confirmation of the principles laid down in T1158/01 and set out in the preceding paragraph. Question (3) hints at a further decision relating to second generation divisional applications, T0797/02 of the same BoA (see http://legal.european-patent-office.org/dg3/biblio/ t020797eu1.htm). T0797/02 rules that any further divisional applications divided out of the parent application must be directed to objects encompassed by invention(s) defined in the claims of the parent application as divided out of the grandparent application. A similar approach was taken earlier by the German Supreme Court but has been given up in favor of a pragmatic approach that considers the division of a patent merely a procedural measure.

The outcome of the proceedings before the Enlarged Board of Appeal cannot be foreseen. Thus, the question arises of how to deal with patent applications that are close to grant and for which a divisional application is to be filed.

The first strategy is to copy the parent application as filed and then file it again as divisional. The advantage is that the applicant can be sure that no subject matter has been added. Thus, the divisional should at least be valid. However, the subject matter to be prosecuted in the divisional is not specifically claimed and thus may not be searched. This potential scenario is the main drawback of this approach. If this subject matter does not form a uniform inventive concept with the originally claimed invention(s) and is not actually searched during the prosecution of the divisional, the applicant will have considerable difficulty amending the claims to cover the subject matter for which the divisional was intended (see Rule 86(4) EPC). It should be kept in mind that no claim amendment between filing and search is possible (Rule 86(1) EPC).

The second strategy is to file new claims but to ensure that these claims (and the divisional application) do not contain any added subject matter. If worst comes to worst, added subject matter that has been overlooked would result in the nullity of the divisional application even if immaterial and not related to claimed subject matter. Thus, this approach is an option when assessment of the added subject matter is clearly feasible and not too time-consuming.

The third strategy is to postpone filing a divisional until the referral to the Enlarged Board of Appeal has been decided. We regard this as the preferable approach in the present situation. This goal can be achieved as follows: The applicant approves the text of the parent case in response to a communication pursuant to R51(4) EPC but requests that dispatch of the decision to grant be postponed until the decision in Case G1/05 is rendered by the Enlarged Board of Appeal, provided this happens in the not too distant future. (Judging from earlier referrals to the Enlarged Board of Appeal, decisions are typically issued within approximately 12 months of referral.) The request should be accompanied by the explanation that the applicant intends to file a divisional application. In view of the fact that (i) the Guidelines are questioned by the referral to the Enlarged Board of Appeal, and (ii) further examination of all divisional applications and patents derived from such applications is stayed if added subject matter is regarded as a decisive issue during the examination or during opposition (see OJ 2005, 606), the postponement should be considered allowable for exceptional circumstances. In case the request is rejected by the EPO, the applicant would have at least seven weeks to make a final examination of the text intended to be filed as a divisional for added subject matter and to file it with the EPO.

In the interest of filing a divisional application in a legally (more) certain environment, this third option is definitely the one to choose. On the other hand, if the grant of the parent application is urgent because "infringers" are already in the market, then either the first or second option should be chosen. Alternatively, for the territory of Germany, the possibility of branching off a utility model out of the parent application should be examined.

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.