(a) A state trust company may deposit trust funds with itself as an investment if authorized by the settlor or the beneficiary, provided:
(1) It maintains as security for the deposits a separate fund of securities, legal for trust investments, under control of a federal reserve bank or other entity approved by the Bank Commissioner, either in this state or elsewhere;
(2) The total market value of the security is at all times at least equal to the amount of the deposit;
(3) The separate fund is designated as such; and
(4) The separate fund is maintained under the control of another trust institution, bank or government agency.
(b) A state trust company may make periodic withdrawals from or additions to the securities fund required by subsection (a) of this section as long as the required value is maintained. Income from the securities in the fund belongs to the state trust company.
(c) Security for a deposit under this section is not required for a deposit under subsection (a) of this section to the extent the deposit is insured by the Federal Deposit Insurance Corporation or its successor.