New York state has sued the maker of McAfee antivirus software alleging it is restricting free speech by barring customers from publishing product reviews without its consent, Attorney General Eliot Spitzer announced Thursday.

Santa Clara, Calif.-based Network Associates Inc., placed restrictions on software diskettes and on its Web site, from which users download software, that explicitly prohibit customers from criticizing products without permission, Spitzer said.

"Network Associates is trying to insulate itself from the type of criticism and commentary that is the essence of the free market," Spitzer said.

The clauses, known as restrictive covenants, are illegal because they harm the public by censoring discussion of a product's flaws and defects, Spitzer contended.

"This clause has a chilling effect on free speech, criticism and public knowledge," Spitzer said. "It is wrong and should be stricken."

Network Associates added the prohibition to make sure customers know that the product they are reviewing is the most updated version, said company general counsel Kent Roberts. The company has since changed the wording of the clause to "take a more suggestive approach."

"We have seen cases where old versions of our products were reviewed on their own and problems were noted that had been fixed by subsequent versions," Roberts said.

In July 1999, Network Associates demanded a retraction of an unfavorable review published in the online and print magazine Network World, citing a clause on its Web site that prohibits product reviews without permission, the lawsuit alleged.

Consumer groups said the lawsuit ensures that users and publishers can continue to independently evaluate software products and discuss their findings publicly.

"Private companies simply should not be permitted to stifle the First Amendment rights of consumers and publishers who buy their products," said James Guest, president and chief executive of Consumers Union.

But Roberts said he does not see a free speech issue because license agreements by nature limit a user's rights.

"Software licensing frequently restricts terms of use," he said. "The bundle of rights can be restricted by the terms of the license so that's why there's not an issue legally with respect to what we did."

The lawsuit, filed in state Supreme Court in Manhattan on Wednesday, seeks to prevent enforcement of any clause restricting product reviews of the company's software, as well as costs and penalties for the company's conduct.

Network Associates, which was founded in 1989 and employs 3,606 workers worldwide, is a leading developer of antivirus and firewall programs. Its revenue for the 2001 fiscal year totaled $834 million.