Ohio Rev. Code Ann. § 1701.791
(B) The agreement of merger or consolidation shall set forth all of the following:
(E) At any time before the filing of the certificate of merger or consolidation under section 1701.81 of the Revised Code, the merger or consolidation may be abandoned by the directors of any constituent corporation, the general partners of any constituent partnership, or the comparable representatives of any other constituent entity if the directors, general partners, or comparable representatives are authorized to do so by the agreement of merger or consolidation. The agreement of merger or consolidation may contain a provision authorizing the directors of any constituent corporation, the general partners of any constituent partnership, or the comparable representatives of any other constituent entity to amend the agreement of merger or consolidation at any time before the filing of the certificate of merger or consolidation, except that, after the adoption of the agreement by the shareholders of any domestic constituent corporation, the directors shall not be authorized to amend the agreement to do any of the following: