(a) Appointment of and acceptance by arbitrator. The parties shall select the arbitrator within 45 days after the arbitration is initiated, or within such other period as is mutually agreed after the initiation of arbitration, and shall mail to the designated arbitrator a notice of his or her appointment. The notice of appointment shall include a copy of the notice or agreement initiating arbitration, a statement that the arbitration is to be conducted in accordance with this part, and a request for a written acceptance by the arbitrator. The arbitrator's appointment becomes effective upon his or her written acceptance, stating his or her availability to serve and making any disclosures required by paragraph (b) of this section. If the arbitrator does not accept in writing within 15 days after the notice of appointment is mailed or delivered to him or her, he or she is deemed to have declined to act, and the parties shall select a new arbitrator in accordance with paragraph (d) of this section.

(b) Disclosure by arbitrator and disqualification. Upon accepting the appointment, the arbitrator shall disclose to the parties any circumstances likely to affect his or her impartiality, including any bias or any financial or personal interest in the result of the arbitration and any past or present relationship with the parties or their counsel. If any party determines that the arbitrator should be disqualified because of the information disclosed, that party shall notify all other parties and the arbitrator no later than 10 days after the arbitrator makes the disclosure required by this paragraph (but in no event later than the commencement of the hearing under § 4221.6). The arbitrator shall then withdraw, and the parties shall select another arbitrator in accordance with paragraph (d) of this section.

(c) Challenge and withdrawal. After the arbitrator has been selected, a party may request that he or she withdraw from the proceedings at any point before a final award is rendered on the ground that he or she is unable to render an award impartially. The request for withdrawal shall be served on all other parties and the arbitrator by hand or by certified or registered mail and shall include a statement of the circumstances that, in the requesting party's view, affect the arbitrator's impartiality and a statement that the requesting party has brought these circumstances to the attention of the arbitrator and the other parties at the earliest practicable point in the proceedings. If the arbitrator determines that the circumstances adduced are likely to affect his or her impartiality and have been presented in a timely fashion, he or she shall withdraw from the proceedings and notify the parties of the reasons for his or her withdrawal. The parties shall then select a new arbitrator in accordance with paragraph (d) of this section.

(d) Filling vacancies. If the designated arbitrator declines his or her appointment or, after accepting his or her appointment, is disqualified, resigns, dies, withdraws, or is unable to perform his or her duties at any time before a final award is rendered, the parties shall select another arbitrator to fill the vacancy. The selection shall be made, in accordance with the procedure used in the initial selection, within 20 days after the parties receive notice of the vacancy. The matter shall then be reheard by the newly chosen arbitrator, who may, in his or her discretion, rely on all or any portion of the record already established.

(e) Failure to select arbitrator. If the parties fail to select an arbitrator within the time prescribed by this section, either party or both may seek the designation and appointment of an arbitrator in a United States district court pursuant to the provisions of title 9 of the United States Code.