(a) A state trust company may deposit trust funds with itself as an investment if:
(1) the deposit is authorized by the settlor or beneficiary;
(2) the state trust company maintains as security for the deposit a separate fund of securities, legal for trust investments, under control of a federal reserve bank or a clearing corporation, as defined by Section 8.102, Business & Commerce Code, within or outside this state;
(3) the total market value of the security is at all times at least equal to the amount of the deposit; and
(4) the separate fund is designated as a separate fund.
(b) A state trust company may make periodic withdrawals from or additions to a securities fund required by Subsection (a) 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) to the extent the deposit is insured by the Federal Deposit Insurance Corporation or its successor.