The commissioner shall not approve an amendment effecting a decrease in the capital stock if the decrease will cause the capital stock to be less than the minimum capital stock required of banks on their organization under this act as specified in section 4; except that, in the case of banks organized prior to the effective date of this act, the commissioner may approve decreases in capital stock if he shall determine that such decreases are necessary for the continuance of an established banking business, and that the continuance of such business is in the public interest, and that,
N.J.S. § 17:9A-121