Any certificate or permit may be transferred or leased subject to the approval of the commission and under such rules and regulations as may be prescribed by the commission. Except where a transfer of a certificate or a permit results from the operation of law, approval of such transfer or lease shall be given only upon a finding by the commission, after notice and opportunity for a hearing, that such transfer or lease will be consistent with the public interest. The application for approval shall be made jointly by the transferor and the transferee or lessor and lessee. No value shall be allowed for any purpose for any certificate or permit issued under this chapter.