(1) Not less frequently than once during each period of 3 months a trust company administering a collective investment fund shall determine the value of the assets in the fund as of the date set for the valuation of assets. No participation shall be admitted to or withdrawn from the fund except: (a) On the basis of such valuation, and (b) as of such valuation date, (c) no participation shall be admitted to or withdrawn from the fund unless a written request for or notice of intention of taking such action shall have been entered on or before the valuation date in the fiduciary records of the trust company and approved in such manner as the board of directors shall prescribe, and (d) no requests or notice may be canceled or countermanded after the valuation date. However, in the case of a fund that is invested primarily in real estate or other assets that are not readily marketable, the value of the fund's assets shall be determined at least once each year.

(2) When participations are withdrawn from a collective investment fund, distributions may be made in cash or ratably in kind, or partly in cash and partly in kind, provided that all distributions as of any one valuation date shall be made on the same basis.

(3) If for any reason an investment is withdrawn in kind from a collective investment fund for the benefit of all participants in the fund at the time of such withdrawal and such investment is not distributed ratably in kind, it shall be segregated and administered or realized upon for the benefit ratably of all participants in the collective investment fund at the time of withdrawal.

(4) Any trust company administering a collective investment fund shall have the responsibility of maintaining in cash and readily marketable investments such part of the assets of the fund as shall be deemed to be necessary to provide adequately for the needs of participants and to prevent inequities between such participants, and if prior to any admissions to or withdrawals from a fund the trust company shall determine that after effecting the admissions and withdrawals which are to be made less than 40 percent of the value of the remaining assets of the collective investment fund would be composed of cash and readily marketable investments, no admissions to or withdrawals from the fund shall be permitted as of the valuation date upon which such determination is made: Provided, That ratable distribution upon all participations shall not be so prohibited in any case.