17 CFR § 240.17Ad-3 - Limitations on expansion.
(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:
(1) Initiate the performance of any transfer agent function or activity for an issue for which the transfer agent does not perform, or is not under agreement to perform, transfer agent functions prior to such fifth business day; and
(2) With respect to an issue for which transfer agent functions are being performed on such fifth business day, initiate for that issue the performance of an additional transfer agent function or activity which the transfer agent does not perform, or is not under agreement to perform, prior to such fifth business day.
(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.