dissenting:

With all due respect for my colleagues, I am constrained to dissent. All recognize that arbitrators have broad discretion to interpret collective bargaining agreements in light of their experience and insight into the inner workings of Industrial America. See, e.g., United Steelworkers of America v. Enterprise Wheel & Car Corp., 363 U.S. 593, 597 , 80 S.Ct. 1358, 1361 , 4 L.Ed.2d 1424 (1960); George Day Construction Co. v. United Brotherhood of Carpenters, 722 F.2d 1471, 1477 (9th Cir.1984). It is not, however, within the arbitrator’s discretion to resolve a perceived conflict between two contractual provisions by making one of them a nullity if both can be preserved by a perfectly plausible interpretation. See Federated Employers of Nevada, Inc. v. Teamsters Local No. 631, 600 F.2d 1263, 1265 (9th Cir.1979). This is especially so where the provision that is given no effect is a valid supplement to the earlier contract provision alleged to be conflicting.

The arbitrator’s conclusion that any promotion through the Job Preference Program must be subject to the confines of the seniority system nullifies the program entirely. Under the arbitrator’s interpretation, workers cannot pursue nontraditional promotional opportunities, which is the only conceivable purpose of the contract clause in question. The only substance that the arbitrator’s decision ascribes to the Job Preference Program is to open new routes of promotion, but since these new routes are still subject to the seniority rules, that does not comport with the obvious purpose of the supplement. The majority’s attempt to find more in the arbitrator’s decision is unavailing. There is simply no escape from the fact that even this labored interpretation preserves the complete hegemony of the seniority system in the face of an agreement clearly intended to modify it. Every worker will have to wait for all the other workers with a longer tenure to be promoted before becoming *828 eligible for promotion. Thus, the arbitrator’s decision negates any benefit to those very workers for whom the supplement was adopted. Unlike the majority, I am unable to conclude that this emasculation of the Job Preference Program is a permitted or plausible interpretation of the contract. In my view, the district court was correct on this principal issue, and I would affirm its judgment.