If only a part of the international application has been searched by the International Searching Authority because that Authority considered that the application did not comply with the requirement of unity of invention, and the applicant did not pay all additional fees according to Article 17, paragraph 3(a), of the Cooperation Treaty within the prescribed time limit, the European Patent Office shall consider whether the application complies with the requirement of unity of invention. If the European Patent Office considers that this is not the case, it shall inform the applicant that a European search report can be obtained in respect of those parts of the international application which have not been searched if a search fee is paid for each invention involved within a period specified by the European Patent Office which may not be shorter than two weeks and may not exceed six weeks. The Search Division shall draw up a European search report for those parts of the international application which relate to inventions in respect of which search fees have been paid. Rule 46, paragraph 2, shall apply mutatis mutandis.