In a proceeding pursuant to CPLR 7504 seeking appointment of an arbitrator, the appeal is from a judgment of the Supreme Court, Kings County (G. Aronin, J.), entered October 31, 1989, which granted the petition and directed the parties to proceed to arbitration.
Ordered that the judgment is affirmed, with costs.
The appellants are owners of certain real property located in Brooklyn. The petitioner is the tenant of the premises pursuant to a lease dated May 1, 1947. The lease provided for an initial 21-year term, with options to renew for two additional terms of the same duration. The petitioner exercised its right to renew for the final term, which runs from May 1, 1989, to April 30, 2010. However, the parties could not agree on an annual rent.
Article I of the lease provides for arbitration in the event the parties have not agreed on a renewal rent after a specific negotiation period. Pursuant to the lease, the appellants appointed Robert Brennan as their arbitrator within 10 days after the negotiation period expired. However, the record establishes that the appellants disregarded their designation of Mr. Brennan and allowed, if not instructed, Terence Tener to negotiate on their behalf. If two parties voluntarily elect to proceed with arbitration in an informal and casual manner, the parties "must be held to have waived any procedural rights which they might otherwise have had and to have accepted the arbitration as they chose to conduct it” (see, Matter of American Ins. Co. [Messinger—Aetna Cas. & Sur. Co.], 43 NY2d 184, 191). Thus, the court did not err when it declared Terence Tener to be the appellants’ arbitrator.
Further, the record establishes that Robert Dombal was chosen by the parties’ arbitrators as umpire. Thus, the court properly designated Mr. Dombal as umpire. Thompson, J. P., Kunzeman, Lawrence and O’Brien, JJ., concur.