Safekeeping of pledged securities; acceptance, release

and substitution. A. Whenever securities pledged by a depository bank or savings and loan association to secure public money are delivered to a custodial bank for safekeeping, the custodial bank is authorized to comply with the written instructions given by the depository bank or savings and loan association and the treasurer of the state, county, municipality, school district, public institution or board involved in accepting the securities for safekeeping, in releasing and delivering all or any portion of such pledged securities held in safekeeping and in permitting substitutions of other approved securities for those previously held in safekeeping. It is not necessary for the custodial bank to obtain instructions from or approval thereof by the board of finance having control of the public money involved in the particular transaction. B. In other cases where a depository bank or savings and loan association is entitled to a withdrawal and return to it of securities which have been deposited to secure deposits of public money, the securities may be withdrawn or substitution of other approved securities effected upon the written instructions executed by the depository bank or savings and loan association and by the treasurer of the state, county, municipality, school district, public institution or board involved. It is not necessary for the instructions to be executed by the board of finance having control of the public money involved in the particular transaction. C. The written instructions specified in Subsections A and B of this section may be contained in the written agreement between the depository bank or savings and loan association and the custodial bank provided for in Section 6-10-21 NMSA 1978.