Upon consideration of the issues a second or subsequent time, or upon a determination of patentability of all claims, the examiner shall issue an Office action treating all claims present in the inter partes reexamination, which may be an action closing prosecution. The Office action shall set forth all rejections and determinations not to make a proposed rejection, and the grounds therefor. An Office action will not usually close prosecution if it includes a new ground of rejection which was not previously addressed by the patent owner, unless the new ground was necessitated by an amendment.