A lobbying group backed by a VeriSign rival filed a lawsuit on Monday challenging last month's settlement deal between VeriSign and the Internet Corporation for Assigned Names and Numbers (ICANN), the regulatory group that oversees the Internet's technical infrastructure.

The Coalition for ICANN Transparency (CFIT) filed suit alleging antitrust violations and illegal competitive acts on VeriSign's part, abetted by ICANN. It wants the court to invalidate the settlement arrangement between VeriSign and ICANN and order the two organisations to stick with the terms of their current .com domain operation until its scheduled expiration in 2007.

VeriSign and ICANN ended nearly two years of legal wrangling with a deal last month that laid the foundation for establishing processes to smooth interactions between the DNS's (Domain Name System) overseer and one of its key services providers. The October agreement extends VeriSign's contract to operate the .com domain name registry through 2012 and sets up a system for rapid ICANN decision making about approval of proposed new VeriSign services.

It's the easing of VeriSign's ability to launch new domain name services that worries Canadian domain-name services company Momentous.ca, CFIT's ringleader. One of Momentous.ca's subsidiaries, Pool.com, filed a lawsuit against VeriSign in 2003 after VeriSign launched a domain wait-list service that directly competed with Pool.com's offerings. Momentous.ca Corp. fears that VeriSign's unfettered ability to launch new products would destroy smaller rival vendors.

"VeriSign's conduct makes it abundantly clear that it has no intention of reigning in its illegal monopolistic imperialism until it has conquered every market related to Internet domain names," CFIT wrote in its lawsuit. "This is an action to preserve the status quo in markets related to Internet domain names, and to prevent VeriSign from expanding its monopoly control over the .com and .net domain name registries into downstream and adjacent markets."

VeriSign had no immediate comment on CFIT's lawsuit.