No registered investment company shall have a majority of its board of directors consisting of persons who are officers, directors, or employees of any one bank (together with its affiliates and subsidiaries) or any one bank holding company (together with its affiliates and subsidiaries) (as such terms are defined in section
1841 of title
12) or any one savings and loan holding company, together with its affiliates and subsidiaries (as such terms are defined in section
1467a of title
12),, except that, if on March 15, 1940, any registered investment company had a majority of its directors consisting of persons who are directors, officers, or employees of any one bank, such company may continue to have the same percentage of its board of directors consisting of persons who are directors, officers, or employees of such bank.