The issuer's duty to file any reports required under section 13(a) shall be suspended immediately upon filing a certification on Form 15; Provided, however, That if the certification on Form 15 is subsequently withdrawn or denied, the issuer shall, within 60 days after the date of such withdrawal or denial, file with the Commission all reports which would have been required had the certification on Form 15 not been filed. If the suspension resulted from the issuer's merger into, or consolidation with, another issuer or issuers, the certification shall be filed by the successor issuer.
17 CFR § 240.12g-4
Termination of registration of a class of securities under section 12(g) of the Act (15 U.S.C. 78l(g)) shall take effect 90 days, or such shorter period as the Commission may determine, after the issuer certifies to the Commission on Form 15 ( 249.323 of this chapter) that the class of securities is held of record by:
(1) Fewer than 300 persons, or in the case of a bank; a savings and loan holding company, as such term is defined in section 10 of the Home Owners' Loan Act (12 U.S.C. 1461); or a bank holding company, as such term is defined in section 2 of the Bank Holding Company Act of 1956 (12 U.S.C. 1841), 1,200 persons; or
(2) Fewer than 500 persons, where the total assets of the issuer have not exceeded $10 million on the last day of each of the issuer's most recent three fiscal years.