(a) If the ownership or operation of a farm changes in such a manner that the agreement no longer contains the signatures of the persons required by § 633.6(a) to sign the agreement, the agreement shall be modified to reflect the new interested persons and new divisions of payments.

(b) If such persons are not willing to become parties to the modified agreement or for any other reason a modified agreement is not executed, the agreement shall be terminated and all unearned payments shall be forfeited or refunded.

(c) The annual payment for the year in which the change of ownership or operation occurs shall not be considered to have been earned unless the designated acreage is continued in the program and there is compliance with the agreement for the full agreement year.

(d) The signatories to the agreement prior to the change of ownership or operation shall be jointly and severally responsible for refunding the unearned payments previously made.