Collective investments of funds or other property held by such qualified fiduciary (and referred to in this paragraph as "collective investment funds") shall be administered as follows:

(1) Each collective investment fund shall be established and maintained in accordance with a written plan (referred to herein as the plan) which shall be approved by a resolution of the trust company's board of directors or by a committee authorized by the board and filed with the director of the department of financial institutions. The plan shall contain appropriate provisions not inconsistent with the rules and regulations of the director of the department of financial institutions as to the manner in which the fund is to be operated, including provisions relating to the investment powers and a general statement of the investment policy of the trust company with respect to the fund; the allocation of income, profits and losses; the terms and conditions governing the admission or withdrawal of participations in the fund; the auditing of accounts of the bank with respect to the fund; the basis and method of valuing assets in the fund, setting forth specific criteria for each type of asset; the minimum frequency for valuation of assets of the fund; the period following each such valuation date during which the valuation may be made (which period in usual circumstances should not exceed 10 business days); the basis upon which the fund may be terminated; and such other matters as may be necessary to define clearly the rights of participants in the fund. A copy of the plan shall be available at the principal office of the trust company for inspection during all banking hours, and upon request a copy of the plan shall be furnished to any person.

(2) Property held by a bank in its capacity as trustee of retirement, pension, profit sharing, stock bonus, or other trusts which are exempt from federal income taxation under any provisions of the Internal Revenue Code may be invested in collective investment funds established under the provisions of subparagraph (a) or (b) of WAC 208-536-040, subject to the provisions herein contained pertaining to such funds, and may qualify for tax exemption pursuant to section 584 of the Internal Revenue Code. Assets of retirement, pension, profit sharing, stock bonus, or other trusts which are exempt from federal income taxation by reason of being described in section 401 of the code may be invested in collective investment funds established under the provisions of subparagraph (b) of WAC 208-536-040, if the fund qualifies for tax exemption under Revenue Ruling 56-267 and following rulings.

(3) All participants in the collective investment fund shall be on the basis of a proportionate interest in all of the assets. In order to determine whether the investment of funds received or held by a trust company as fiduciary in a participation in a collective investment fund is proper, the trust company may consider the collective investment fund as a whole and shall not, for example, be prohibited from making such investment because any particular asset is nonincome producing.