Except as provided under section 91105(c), collective-bargaining agreements between the Corporation and bargaining representatives shall be effective for not less than 2 years. (b) Procedures Collective-bargaining agreements between the Corporation and bargaining representatives recognized under section 91105 may include procedures for resolution by the parties of grievances and adverse actions arising under the agreement, including procedures culminating in binding third-party arbitration, or the parties may adopt such procedures by mutual agreement in the event of a dispute. Such procedures shall be applicable to disputes arising under section 91109. (c) Limitation on application Notwithstanding section 91103, section 7121(c) of title 5 shall not apply to this chapter. (d) Dispute resolution procedures The Corporation and bargaining representatives recognized under section 91105 may by mutual agreement adopt procedures for the resolution of disputes or impasses arising in the negotiation of a collective-bargaining agreement. 91107. Collective-bargaining dispute resolution (a) Resolution of disputes (1) In general If, prior to 90 days after the expiration of the term collective-bargaining agreement or 90 days after the parties begin mid-term negotiations, the Corporation and the exclusive bargaining representative of the employees of the Corporation (in this section referred to collectively as the parties ) do not reach an agreement under sections 7114(a)(1), 7114(a)(4), and 7114(b) of title 5 (as such sections apply to the Corporation under this chapter), or section 91106(d) of this chapter, the Corporation and the bargaining representative shall use the mediation services of the Service to attempt to reach such agreement in accordance with part 1425 of title 29, Code of Federal Regulations (as in effect on the date of enactment of this subtitle). (2) Mediation period The mediation period under paragraph (1) may not exceed 60 days unless extended by written agreement of the parties. (b) Binding arbitration for