(a) If, after a reasonable period of negotiation over the terms of a collective bargaining agreement, an impasse as determined by the railroad labor relations agency exists between the corporation and an organization, the railroad labor relations agency shall appoint a person mutually agreeable to the parties from a list of seven qualified mediators or arbitrators knowledgeable in railway labor agreements to act as mediator in the dispute.
(b) Before the determination of an impasse under this section, the parties may also select a mediator by mutual consent.
(c) It shall be the function of the mediator to bring the parties together to effectuate a settlement of the dispute, but neither the mediator nor the railroad labor relations agency has any power of compulsion in mediation proceedings.