(a) Unless determined on a motion to dismiss, petitions to review orders reviewable under this chapter are heard in the court of appeals on the record of the pleadings, evidence adduced, and proceedings before the agency, when the agency has held a hearing whether or not required to do so by law.

(b) When the agency has not held a hearing before taking the action of which review is sought by the petition, the court of appeals shall determine whether a hearing is required by law. After that determination, the court shall—

(1) remand the proceedings to the agency to hold a hearing, when a hearing is required by law;

(2) pass on the issues presented, when a hearing is not required by law and it appears from the pleadings and affidavits filed by the parties that no genuine issue of material fact is presented; or

(3) transfer the proceedings to a district court for the district in which the petitioner resides or has its principal office for a hearing and determination as if the proceedings were originally initiated in the district court, when a hearing is not required by law and a genuine issue of material fact is presented. The procedure in these cases in the district court is governed by the Federal Rules of Civil Procedure.

(c) If a party to a proceeding to review applies to the court of appeals in which the proceeding is pending for leave to adduce additional evidence and shows to the satisfaction of the court that—

(1) the additional evidence is material; and

(2) there were reasonable grounds for failure to adduce the evidence before the agency;

the court may order the additional evidence and any counterevidence the opposite party desires to offer to be taken by the agency. The agency may modify its findings of fact, or make new findings, by reason of the additional evidence so taken, and may modify or set aside its order, and shall file in the court the additional evidence, the modified findings or new findings, and the modified order or the order setting aside the original order.