The lives of a group of individuals may be insured under a policy issued to the trustees of a fund established by two or more employers or by two or more employer members of an employers' association, or by one or more labor unions, or by one or more employers and one or more labor unions, or by one or more employers and one or more labor unions whose members are in the same or related occupations or trades, which trustees shall be deemed the policyholder, to insure employees or members for the benefit of persons other than the employers or the unions, subject to the following requirements:

(1) If the policy is issued to two or more employer members of an employers' association, such policy may be issued only if (a) the association has been in existence for at least five years and was formed for purposes other than obtaining insurance and (b) the participating employers, meaning such employer members whose employees are to be insured, constitute at date of issue at least fifty percent of the total employers eligible to participate, unless the number of persons covered at date of issue exceeds six hundred, in which event such participating employers must constitute at least twenty-five percent of such total employers in either case omitting from consideration any employer whose employees are already covered for group life insurance.

(2) The persons eligible for insurance shall be all of the employees of the employers or all of the members of the unions, or all of any class or classes thereof determined by conditions pertaining to their employment, or to membership in the unions, or to both. The policy may provide that the term "employees" shall include the individual proprietor or partners if an employer is an individual proprietor or a partnership. The policy may provide that the term "employees" shall include the trustees or their employees, or both, if their duties are connected with such trusteeship. The policy may provide that the term "employees" shall include retired employees.

(3) The premium for the policy shall be paid by the trustees wholly from funds contributed by the employer or employers of the insured persons, or by the union or unions, or partly or wholly from funds contributed by the insured persons, or any combination thereof. A policy on which all or part of the premium is to be derived from funds contributed by the insured persons specifically for their insurance may be placed in force if the eligible persons elect to make the required contributions. A policy on which no part of the premium is to be derived from funds contributed by the insured persons specifically for their insurance must insure all eligible persons, or all except any as to whom evidence of individual insurability is not satisfactory to the insurer.

(4) The policy must cover at least twenty persons at date of issue.

(5) The amounts of insurance under the policy must be based upon some plan precluding individual selection either by the insured persons or by the policyholder, employers, or unions.