T 0936/04 (Double patenting/CONOCO) vom 24.04.2008

Double patenting (no)
Amendments - allowable (yes)
Remittal - (yes)

(1) Double patenting is not a ground of opposition. It is within the discretion of the instances of the EPO to raise the objection in opposition or opposition appeal proceedings against proposed amended claims, but this should be done only in clear cases. The purpose behind the principle of prohibition of double patenting is to avoid unnecessary duplication of effort, and not to impose on the instances of the EPO an obligation to make a complex comparison between the case before them and the claims that may have been granted in some other proceedings (see Reasons section 2 on double patenting, in particular Point 2.3).
(2) Where at the time of the decision by the opposition division no patent had yet been granted on the divisional application, then for this reason alone the opposition division was correct to disregard the objections of double patenting raised before it. At that stage it would be only a matter for the Examining Division, in the proceedings on the divisional application before it, to avoid double patenting by allowing again claims already granted in the parent patent (see Reasons, Point 2.2).