Any agreement may be renewed or extended at the end of the
agreement period for an additional period of ten years by mutual
agreement of the Secretary and the owner or operator, subject to
any rate redetermination by the Secretary. If during the agreement
period the owner or operator sells or otherwise divests himself of
the ownership or right of occupancy of such land, the new owner or
operator may continue such agreement under the same terms or
conditions, or enter into a new agreement in accordance with the
provisions of this chapter, including the provisions for renewal
and adjustment of payment rates, or he may choose not to
participate in such program.