OPINION OF THE COURT
Ross, J.A narrow issue is presented for our review—whether the wage rate arbitration clause contained in the lease between these parties is sufficiently comprehensive in scope as to require arbitration where the defendant landlord adjusts his method of calculating the wage rate for certain building personnel, resulting in an increased rental to the *54plaintiff tenant. We conclude that this issue is a proper subject for arbitration.
The plaintiff and defendant entered into a multiyear lease whereby the plaintiff now rents approximately 45% of the available rental space in defendant’s prestigious building. The controversy in which these parties are now embroiled finds its genesis in article 7 of this lease which provides for a rental increase if there is a corresponding wage increase for porters and cleaning women. However, the wage rates of these personnel are determined by a collective bargaining agreement to which neither the landlord nor the tenant is a party. Once the subject wage rates are contractually established, it is incumbent upon the landlord to calculate the impact these rates will have on the lease between plaintiff and defendant.
Section 7.01 of the lease provides,.in pertinent part, that: “The Wage Rate shall include but not be limited to sums paid for pensions, welfare funds, vacations, bonuses, social security, unemployment, disability benefits, health, life, accident and other types of insurance * * * The Base Wage Rate shall mean the Wage Rate in effect on December 31, 1969.” Under this all inclusive definition, it comes as no surprise that since 1972 to the present, the “Wage Rate” has always exceeded the base rate, thus requiring a re-computation in the rent to be paid. In calculating a rent increase the landlord must follow an established formula:
“If the Wage Rate shall be changed at any time after December 31, 1969, and shall be greater than the Base Wage Rate at any time(s) during the term of this lease, Tenant shall pay to Landlord as additional rent an annual sum equal to 1.10 times the product obtained by multiplying (i) the number of cents, by which the Wage Rate exceeds the Base Wage Rate by (ii) the number of square feet of rentable area of the demised premises. * * *
“Landlord shall give Tenant written notice of each change in the Wage Rate which will be effective to create or change Tenant’s obligation to pay additional rent * * * and such notice shall contain Landlord’s calculation of the annual rate of additional rent payable resulting from such change in the Wage Rate” (§ 7.02).
*55As mentioned above the wage rates for porters and cleaning women are established by a collective bargaining agreement and are expressed in hourly terms. However, fringe benefits are not similarly denoted. This integral part of the wage rates is provided for on a yearly or weekly basis. It is then necessary to translate the latter portion of the wage rates into the- common denominator of hourly rates. During the years 1972-1979, the landlord translated the nonhourly fringe benefit rates into hourly rates by taking the benefits and, if they were expressed in annual terms, the landlord divided that amount of the benefit by 2,080 hours for the porters (40 hours per week times 52 weeks) and by 1,560 hours for the cleaning women (30 hours per week times 52 weeks). If the benefit was expressed in weekly terms, the landlord divided that amount of the benefit by 40 hours for the porters and 30 hours for the cleaning women. In addition, beginning sometime after 1972, the landlord began to divide vacation time by 2,000 hours for porters and 1,500 hours for cleaning women representing 40- and 30-hour work weeks respectively multiplied by 50 weeks rather than 52 weeks.
For the years 1975 through and including 1979, the tenant protested the wage rate escalation notices provided by the landlord. For the three-year period commencing with 1977, the tenant sought to arbitrate this increase pursuant to the wage rate arbitration clause contained in their lease. This provision provides in pertinent part: “Every notice given by the Landlord pursuant to Section 7.02 shall be conclusive and binding upon tenant unless (i) within 45 days after receipt of such notice Tenant shall notify Landlord that it disputes the correctness of the notice, specifying the particular respects in which the notice is claimed to be incorrect, and (ii) if such dispute shall not have been settled by agreement, shall submit the dispute to informal arbitration pursuant to Article 33 within 90 days after receipt of the notice.” It is interesting to note that even though the tenant sought to arbitrate the change in wage rates for three years, to date these proceedings have not commenced.
By notice dated February 1, 1980, landlord provided tenant with the first notice of a change in wage rates for *561980 and the landlord’s calculation of additional rent payable. It is this first 1980 notice which constitutes the subject of this appeal. The 1980 increase, according to this notice, was the result of a wage increase negotiated for the porters and cleaning women. Additionally, landlord notified tenant that he, the landlord, had adjusted the method of determining the hourly rate for fringe benefits by dividing the benefits by the hours actually worked. Now, instead of using the annual figure of 2,080 hours for porters and 1,560 hours for cleaning women, the landlord used the figures of 1,657 for porters and 1,221 for cleaning women. Similarly, the landlord divided the base wage rate by actual hours worked in the 1969 base year.
Tenant timely protested this latest notice and demanded arbitration. Simultaneously, tenant also commenced an action at law against the landlord concerning .the 1980 wage escalation notice. Both the action at law and the demand for arbitration challenge the propriety of the landlord adopting a new method of calculating the hourly rate for fringe benefits.
Tenant moved to stay its own demand for arbitration on the grounds that the causes of action set forth in the complaint are “justiciable and not arbitrable.” Landlord countered by moving to stay the action at law and permit the arbitration to proceed. Special Term denied the landlord’s motion to stay the law action and we now reverse this determination.
The landlord’s 1980 adjustments, in which he utilized a novel approach, is an appropriate issue for arbitration as stipulated by the lease voluntarily entered into between these parties. Article 7 of the document defined wage rates to include fringe benefits and is silent as to any approved method in determining how to translate fringe benefits into hourly rates. If these rates escalated for whatever reason, the landlord was obligated to notify the tenant and include in this notice the calculations upon which this increase was based. If there was a dispute, arbitration was the elected forum. Since the wage rates were negotiated through a collective bargaining process, a matter in which these parties had no input the only dispute that could arise *57would center around the landlord’s calculations thereof. Therefore, under the lease agreement a change in landlord’s method of calculation of the wage rate is a change in the wage rate which may be challenged only through arbitration. The agreement to arbitrate is thus “express, direct, and unequivocal” (Gangel v DeGroot, 41 NY2d 840, 841).
It is well established that the tenant, who is now assailing this provision, has on prior occasions indicated that arbitration is the preferred forum. In fact it is the only forum in which tenant has previously attempted to resolve disputes pertaining to the translation of fringe benefits into hourly rates. This fact is accorded little attention by our dissenting colleague. The dissent argues that the increased rent is based upon adoption of a new formula for the computation of the wage rate, and since tenant never specifically agreed to arbitrate that individual issue, it cannot be required to arbitrate at all. The record indicates that the provisions of the lease do not discuss how the landlord is to convert fringe benefits into an hourly rate. In addition to no formula being set forth, the tenant concedes that the landlord previously utilized two different methods of computation to translate the weekly and annual fringes into an hourly rate and that they (Avon) demanded arbitration on at least two occasions. The Court of Appeals recently held that: “Once the parties to a broad arbitration clause have made a valid choice of forum, as here, all questions with respect to the validity and effect of subsequent documents purporting to work a modification or termination of the substantive provisions of their original agreement are to be resolved by the arbitrator” (Schlaifer v Sedlow, 51 NY2d 181). When defendant previously attempted to recompute the rent, there was no question that arbitration was the sole forum in which to seek redress. To hold that a party has relinquished his right to litigate, it must be shown that the parties intended or contemplated the use of arbitration. We feel that the record amply demonstrates that the parties to this action so intended. Through the lease and through their prior course of dealings these parties have clearly demonstrated that they have “expressly agreed to *58arbitrate their disputes” (Schubtex, Inc. v Allen Snyder, Inc., 49 NY2d 1, 6).
One additional fact, and one which has been overlooked by the dissent, is that the parties to this lease are by no means neophytes in the business world. They have, through their years of collective experience, attained a certain degree of sophistication in the negotiation, drafting and implementation of lease agreements. They have, through the past decade, interpreted article 7 of the subject lease to be all encompassing. To suddenly contend otherwise would be tantamount to negating that business acumen which has been amassed. The past interpretation given this article need not be recast. Therefore, no reason exists why this issue, like the others preceding it, should not proceed to arbitration.
Accordingly, the order of the Supreme Court, New York County (Wallace, J.), entered on August 28,1980, which denied defendant’s motion to stay this action, pending arbitration, should be reversed, on the law to the extent appealed from, with costs and disbursements, and the motion granted.