The Interstate Commerce Commission, in a major victory for shippers, unanimously declared as an unreasonable practice a collections campaign waged by the auditing company hired by defunct Churchill Truck Lines Inc.

Churchill is the Chillicothe, Mo., less-than-truckload carrier that abruptly closed its doors during the first week of a 28-day Teamster strike in 1994.After being retained by Churchill, Trans-Allied Audit Co. of Minneapolis began dunning scores of shippers in January for balance due claims, contending that an "unambiguous" provision restricted discounts to points that Churchill served on a regular basis. Trans-Allied claimed that Churchill's discounts did not apply on freight hauls to and from regular route points.

Angry shippers, led by the National Small Shipments Traffic Conference's general counsel, Daniel J. Sweeney, fired back on May 11, asking the ICC to halt the barrage of claims as unreasonable.

In petitions, the shippers countered that Trans-Allied was denying published discounts for shipments hauled by Churchill to or from irregular route points on grounds those movements were to points in the carrier's regular route certificates.

Mr. Sweeney charged that Churchill had never contended that the discounts did not apply to shipments moving directly to and from all points for which it held irregular route authority, regardless of whether or not they also happen to be points for which it held regular route authority.

The ICC accepted the argument.

"Churchill/Trans-Allied's attempt to evade the issue presented by petitioners utterly fails," the commission wrote in a July 31 decision that became effective Monday.

The ICC said its decision was backed by arguments from Gutter Suppliers Inc. and Transcraft Corp., which complained that Churchill was submitting balance due claims on grounds that another carrier was involved in their truck service.

Churchill was apparently adopting the view that such moves constituted joint-line service, the ICC said. Because its tariffs were limited to irregular route points served directly by Churchill, any discount rates quoted, accepted and collected did not apply, the carrier claimed.

But the commission said: "In our view, unless a shipper specifically requested the higher-priced joint-line service, Churchill may not collect undercharges."

The ICC's ruling lets shippers off the hook for potentially hundreds of thousands of dollars in undercharge claims, said Joseph F.H. Cutrona, Nasstrac's executive director.

Until the decision, many shippers were electing to settle with Trans-Allied to avoid lengthy and costly court fights, said Mr. Sweeney, of the Washington law firm of McCarthy, Sweeney & Harkaway.

But others, like Anacomp Inc., an Omaha, Neb., maker of floppy disk parts with an $8,073.82 claim, chose to fight. A total of 38 shippers, along with the Transportation Claims & Prevention Council and the National Industrial Transportation League, filed comments and petitions.