Any contract for the borrowing of money or the mortgaging or pledging of the assets of the estate for any of the purposes stated in Section 264 of this title must have the approval of the judge of the district court having jurisdiction of the settlement of the estate and the procedure therefor shall be the same procedure as that provided for in Sections 385-b (as amended), 385-c, and 385-d of this title, except that personal property may be mortgaged or pledged as security for such indebtedness without limitation to two-thirds ( ²/₃ ) of the appraised value thereof.