; and (2) in no case for more than 10 years. (e) Permit modification (1) In general An exploration permit holder may, during the term of the exploration permit, submit to the Secretary concerned an application to modify such permit. (2) Approval of modification To approve a proposed modification to the permit, the Secretary concerned shall make the same determinations as are required in the case of an original permit, except that the Secretary and the Secretary of Agriculture may specify by joint regulation the extent to which requirements for initial exploration permits under this section shall apply to applications to modify an exploration permit based on whether the Secretary concerned determines such modifications are significant or minor. (f) Transfer, assignment, or sale of rights (1) Prior written approval No transfer, assignment, or sale of rights granted by an exploration permit issued under this section may be made without the prior written approval of the Secretary concerned. (2) Approval The Secretary concerned shall allow an exploration permit holder to transfer, assign, or sell rights under such permit to a successor, if the Secretary concerned finds in writing that the successor— (A) is eligible to receive a permit under section 304; (B) has submitted evidence of financial assurance satisfactory under section 306