Trust institutions and foreign trust institutions, as defined by this part, acting in a fiduciary capacity and for fiduciary purposes, if exercising due care as a prudent investor, and with the consent of any cofiduciary, may invest and reinvest funds held in such fiduciary capacity in the shares of stock of one or more fiduciary investment companies, except where the will, trust indenture, or other instrument under which such trust institution or foreign trust institution acts prohibits such investment, provided that the fiduciary investment company, by its articles of incorporation issued and granted in conformity with Chapter 2 of Title 14, shall have and possess the corporate powers required by this part and be subject to the limitations set forth by this part; provided, further, that no such trust institution or foreign trust institution shall invest in the stock of a fiduciary investment company on behalf of any estate, trust, or fund administered by such trust institution or foreign trust institution a sum or amount which would result in such estate, trust, or fund having a total investment in such stock in excess of the maximum amount or percentage that might be invested by such estate, trust, or fund, under the regulations of the department in effect at the time of such investment, in any common trust fund having total assets equal to the total assets of the fiduciary investment company as increased by the proposed investment; and no trust institution or foreign trust institution shall invest in the stock of a fiduciary investment company if, immediately after such investment and as a consequence thereof, it would own more than 25 percent of the voting securities of such fiduciary investment company which would then be outstanding.