A. Subject to such regulations as the commissioner [director of the financial institutions division of the commerce and industry department] may prescribe, a state bank or safe deposit company may maintain and lease safe deposit boxes and may accept property or documents for safekeeping if, except in the case of night depositories, it issues a receipt therefor.
B. A state bank may own stock in safe deposit companies not exceeding in aggregate cost fifteen percent of its capital and surplus, but at least ninety percent of the stock in each such safe deposit company must be owned by banks.