(1) Banks are permitted to underwrite issues of investment securities if the following conditions are met:

(a) No banks having unimpaired capital and surplus of less than $5,000,000 shall underwrite or otherwise participate as principal in the marketing of securities, except for the account of and upon specific instructions from its customer.

(b) Banks that qualify to underwrite or participate by having unimpaired capital and surplus of $5,000,000 or greater, may do so with any securities that such banks could purchase for their own account.

(c) Accounting and other records of trading in such securities must be separately maintained from accounting and other records relating to purchases of securities for the bank's own account.