Nothing in this Act shall be construed to require the approval of any Illinois State authority as a condition to the right of a State bank, pursuant to the laws of the United States or of this State, to be converted into a national bank or insured savings association or to merge with an insured savings association or with a national bank under a national charter. The action to be taken by such merging or converting State bank and its rights and liabilities and those of its stockholders and of its dissenting stockholders shall be the same as those prescribed for a State bank merging with, or converting into, a national bank or insured savings association that has received its charter from an agency of the United States Government at the time of the action by the law of the United States and not by the law of this State unless the State bank merges with or converts to a savings and loan association or savings bank chartered under the laws of this State, except that an affirmative vote of the holders of at least two-thirds of the outstanding shares of stock of a State bank entitled to vote at a meeting called in conformity with Section 23 shall be required for the merger or conversion. Upon the completion of a merger or conversion, resulting in a national bank or insured savings association, the charter of any merging or converting State bank shall automatically terminate. Approval by the Commissioner to convert a State bank to a national bank or insured savings association or to merge a State bank into a national bank or insured savings association shall not be required under this Act. However, any such converting or merging State bank shall notify the Commissioner in writing of the proposed conversion or merger not less than 30 days prior to such conversion or merger and shall pay all accrued or outstanding assessments pursuant to Section 48 of this Act as of the date of conversion or merger.