Any such bank or trust company which is an affiliate of a bank holding company, as the term “affiliate” is defined by the federal Bank Holding Company Act of 1956, as amended, or of a savings and loan holding company as defined by the federal Savings and Loan Holding Company Act, as amended, may establish common trust funds for the purpose of furnishing investments to itself as fiduciary, to other affiliates of the same holding company qualified to act as fiduciary in this state or in any other state, or to itself and others as co-fiduciaries, or to such other affiliates and others as co-fiduciaries. Subject to the limitations upon the investment of funds held in a fiduciary capacity in common trust funds contained in N.H. Rev. Stat. § 391:1, any such bank or trust company establishing such common trust funds and other affiliates of the same holding company qualified to act as fiduciary in this state or in any other state may, as such fiduciary or co-fiduciary, invest funds which it lawfully holds for investment in such common trust funds. Any such bank or trust company may also invest funds which it holds in a fiduciary capacity in any collective investment fund or common trust fund established by such other affiliates of the same holding company under the laws of any state; provided, however, that any such investment is not prohibited by the instrument, judgment, decree, or order creating the fiduciary relationship. Any bank or trust company establishing, maintaining, or so utilizing any common trust fund established under this chapter shall comply with and be subject to all of the provisions of this chapter as though such bank or trust company and the other affiliates participating in such common trust fund were one and the same corporate entity. Any person acting as a co-fiduciary with any such bank or trust company is hereby authorized to consent to the investment in interest in a common trust fund or funds created hereunder.