The Commission may, after consultation with and taking into consideration the views of the Federal banking agencies (as defined in section
1813 of title
12), adopt rules and regulations, and issue orders, consistent with the protection of investors, prescribing the conditions under which a bank, or an affiliated person of a bank, either of which is an affiliated person of a principal underwriter for, or depositor of, a registered unit investment trust, may serve as trustee or custodian under subsection (a)(1) of this section.