The Authority is empowered at any time and from time to time to 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 and premium, if any, and interest on any or all of the bonds (as defined in § 62.1-199) of the Authority. The interests of the Fund in any obligations so transferred shall be subordinate to the rights of the trustee under the pledge. To the extent funds are not available from other sources pledged for such purpose, any payments of principal and interest received on the assets transferred or held in trust may be applied by the trustee thereof to the payment of the principal of and premium, if any, and interest on such bonds of the Authority to which the obligations have been pledged, 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 and premium, if any, and interest on such bonds of the Authority. Any assets of the Fund 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 to secure the bonds of the Authority and shall be held by the trustee to which they are pledged until no longer required for such purpose by the terms of the pledge. On or before the tenth day of January in each year, the Authority shall transfer, or shall cause the trustee to transfer, to the Fund any assets transferred or held in trust as set forth above which are no longer required to be held in trust pursuant to the terms of the pledge.