17 C.F.R. § 240.17Ad-3
(a) Any registered transfer agent which is required to file any notice pursuant to § 240.17Ad-2 (c) or (d) for each of three consecutive months shall not from the fifth business day after the end of the third such month until the end of the next following period of three successive months during which no such notices have been required:
(b) Any registered transfer agent which for each of two consecutive months fails to turn around at least 75% of all routine items in accordance with the requirements of § 240.17Ad-2(a) or to process at least 75% of all items in accordance with the requirements of § 240.17Ad-2(b) shall be subject to the limitations imposed by paragraph (a) of this section and further shall, within twenty business days after the close of the second such month, send to the chief executive officer of each issuer for which such registered transfer agent acts a copy of the written notice filed pursuant to § 240.17Ad-2 (c) or (d) with respect to the second such month.
(Secs. 2, 17, 17A and 23(a) (15 U.S.C. 78b, 78q, 78q-1 and 78w(a)))
[42 FR 32412, June 24, 1977]