(a) Timber sale contracts may be modified only when the modification will apply to unexecuted portions of the contract and will not be injurious to the United States. Modifications may be made by the officer approving the sale, by his successor, or by his superior, except as provided in § 223.110.

(b) Timber sale contracts awarded after October 1, 1995, that have been suspended for more than 90 days, during the normal operating season, at no fault of the purchaser, because of administrative appeals or litigation, that did not include contract provisions for rate redeterminations may be modified at the request of the timber sale purchaser to include a rate redetermination for the remaining unharvested volume to reflect significant decreases in market value during the period of delay. Rates in effect at the time of the suspension will be redetermined in accordance with the standard Forest Service methods in effect 45 days prior to the rate redetermination.