If a private plan does not provide for the assumption by an insurer, duly authorized and admitted to do business in this State, of the liability to pay the benefits afforded by such plan, the commission shall not approve it unless the employer files with the commission the bond of an admitted surety insurer conditioned on the payment of obligations under the plan, or deposits with the commission securities approved by the commission to secure the payment of such obligations. The penal sum of the bond or the amount of the deposit shall be determined by the commission and shall be not less than one-half of the contributions which would have been paid by the employees to be covered by the plan during the previous year, or one-half of the estimated contributions of such employees for the ensuing year, whichever is greater; provided, however, that any employer who is a self-insurer and is exempt from insuring his workmen’s compensation liability, as provided by law, shall so long as such exemption remains in effect be exempt from the surety bond and security deposit requirements of this section; and any other employer who shall satisfy the commission as to the permanence of his business and his financial ability to pay the benefits provided by a private plan submitted for approval may, upon application, be exempted from such requirements by written order of the commission, which order shall be revocable at any time.

L.1948, c. 110, p. 609, s. 30.