The Authority is empowered at any time and from time to time to pledge, assign or transfer from the Fund to banks or trust companies designated by the Authority any or all of the assets of the Fund to be held in trust as security for the payment of the principal of, premium, if any, and interest on any or all of the bonds, as defined in § 62.1-199, issued to finance any project. The interests of the Fund in any assets so transferred shall be subordinate to the rights of the trustee under the pledge, assignment or transfer. To the extent funds are not available from other sources pledged for such purpose, any of the assets or payments of principal and interest received on the assets pledged, assigned or transferred or held in trust may be applied by the trustee thereof to the payment of the principal of, premium, if any, and interest on such bonds of the Authority secured thereby, and, if such payments are insufficient for such purpose, the trustee is empowered to sell any or all of such assets and apply the net proceeds from the sale to the payment of the principal of, premium, if any, and interest on such bonds of the Authority. Any assets of the Fund pledged, assigned or transferred in trust as set forth above and any payments of principal, interest or earnings received thereon shall remain part of the Fund but shall be subject to the pledge, assignment or transfer to secure the bonds of the Authority and shall be held by the trustee to which they are pledged, assigned or transferred until no longer required for such purpose by the terms of the pledge, assignment or transfer.