Mo. Rev. Stat. § 362.580: Common trust fund authorized.

1. Any state or national bank or trust company qualified to act as fiduciary in this state may establish common trust funds for the purpose of furnishing investments to itself as fiduciary, or to itself and others as cofiduciaries, or to other banks and trust companies acting as fiduciaries or cofiduciaries. Funds may be invested in such common trust fund only if the investment is not prohibited by the instrument, judgment, decree, or order creating the fiduciary relationships, and if, in the case of cofiduciaries, the banks or trust companies procure the consent of their cofiduciaries to the investment.

2. This section shall apply to fiduciary relationships now in existence or hereafter established.