N.H. Rev. Stat. § 391:1
Any 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 co-fiduciaries; and may, as such fiduciary or co-fiduciary, invest funds which it lawfully holds for investment in interests in such common trust funds, if such investment is not prohibited by the instrument, judgment, decree, or order creating such fiduciary relationship, and if, in the case of co-fiduciaries, the bank or trust company procures the consent of its co-fiduciaries to such investment. Any person acting as a co-fiduciary with any such bank or trust company is hereby authorized to consent to the investment in such interests.
RSA 391:1
1953, 109:1, par. 1, eff. Apr. 17, 1953.