Rogers, Circuit Judge:
Joseph T. Ryerson & Sons, Inc. petitions for review of an order of the National Labor Relations Board that the company violated ss 8(a)(1) and (5) of the National Labor Relations Act by refusing to bargain with the certified representative of the bargaining unit, namely with Local 714 of the International Brotherhood of Teamsters (“Teamsters”) and the United Steelworkers of America (“Steelworkers”), which jointly petitioned to represent a bargaining unit at four of the company’s plants in Chicago, Illinois. The company contends that the Board erred in failing to set aside the election for three reasons: (1) the Act does not authorize either joint election petitions or separate administration by two unions of a collective bargaining agreement; (2) there is not substantial evidence in the record to support the Board’s finding that the unions did not misrepresent the intended nature of their joint representation to the bargaining unit employees during the election campaign; and (3) the hearing officer abused his discretion in denying the company’s subpoena for the unions’ entire joint bargaining agreement and other internal documents relating to the joint petitions for representation, thereby denying the company a full and fair hearing. Because the company failed to preserve its statutory argument for review by the court, and because we conclude that the company’s other contentions are unpersuasive, we deny the petition and grant the Board’s cross-application for enforcement of its order.