Seeking to extricate itself from a growing legal quagmire in cyberspace, Network Solutions Inc, the company that assigns names for Internet sites, issued a new policy for resolving disputes over addresses. The company, which hands out domain names under an agreement with the US National Science Foundation, said it would shut down a site within 90 days if someone holding a registered trademark to the site’s name makes a challenge. But trademark attorneys and Internet specialists said the company’s new policy would do little to quell the growing controversy. Such disputes are occurring with increasing frequency, usually when a trademark holder discovers someone else is using their mark as the name of an Internet site. However, Network Solutions’s new policy relies too heavily on registered trademarks, while ignoring other forms of legally recognized trademarks, and would not solve an increasingly serious problem, attorneys said.