In his ruling, issued yesterday, US District Judge A Howard Matz dismissed antitrust allegations against ICANN, calling them "awfully vague", reports the Associated Press. The registry now has until 7th June to substantiate the claims.
If it does not succeed the remaining five claims of the suit will have to be transferred to state, rather than federal, court.
The dispute relates, at least in part, to VeriSign's surprise launch of the controversial Site Finder service in September 2003.
This new service redirected surfers to VeriSign's Site Finder search engine when they entered a web address that was not registered on the internet or was inactive. The unilateral change was made, according to VeriSign, to improve "the user web-browsing experience."
But the alteration provoked a barrage of criticism. Network administrators accused VeriSign of seeking not to aid the misguided web user, but rather to generate more advertising revenue from its search engine partners. Others criticised the effect that the changes have had on the working practices of the internet.
ICANN stepped in and, in the face of a threatened court action, VeriSign agreed to suspend the service.
But VeriSign was already smarting from a long battle over its attempt to launch the equally controversial Wait Listing Service (WLS), which invites 'reservations' for domain names that speculators hope to acquire upon expiry of their registration.
VeriSign's proposal required all registrars applying for expiring domain names to apply through VeriSign, and was criticised by domain name registrars and resellers, who argued that the new scheme would increase costs and kill their secondary domain name business model. As yet it is not operational.
In February, VeriSign, impatient with delays and interference, sued ICANN, alleging that the body has overstepped its contractual authority and improperly attempted to regulate VeriSign's business in violation of its charter and its agreements with VeriSign.
VeriSign accused ICANN of improperly attempting to become the de facto regulator of the domain name system and in so doing stifling the introduction of new services that benefit internet users and promote the growth of the internet.
In its complaint, VeriSign explained that it had attempted to work with ICANN within an agreed framework to introduce new services, including recent discussions regarding the Wait Listing Service. But over the last several years, said VeriSign, ICANN had failed to follow a clear, consistent and uniform process.
The case is seen by many as an attempt by VeriSign to assert its own authority as the leading internet organisation.
After the ruling, VeriSign spokesman Brian O'Shaughnessy told CNET News.com: "We ultimately believe we'll prevail on the matter".