FRAMINGHAM (10/24/2003) - Qwest Communications International Inc. this week sued AT&T Corp., alleging inaccurate billing of toll-free calls routed across the Qwest network. Qwest is seeking to recoup fees from AT&T lost to under-billing based on an inaccurate AT&T database of toll-free calls using Qwest's network. Qwest says that the under-billing amounted to US$15 million to $20 million annually. AT&T denies the allegations in Qwest's lawsuit. "In the normal course of our ongoing business arrangements with Qwest, this is a contract and billing dispute that we have been working to resolve for more than the past 16 months," an AT&T spokesperson said. "We will file a formal reply to the complaint in U.S. District Court at the appropriate time." Qwest says AT&T stopped updating the toll-free number database over three years ago and informed Qwest of this last year. New toll-free numbers routed through the Qwest network since March 2000 were billed incorrectly at a lower access rate, she said.