"We are not in discussions with Microsoft or any other company to buy Network Associates," said Jennifer Keavney, a spokeswoman for the company.
The statement came after a trade magazine published an article quoting unnamed Wall Street sources and partners as saying that the company was on the block and considering a deal with Microsoft.
Network Associates normally stays mum on such speculation, Keavney said, but the level of interest in this rumour required a response. Network Associates chief executive George Samenuk was a presenter at the Wachovia Securities 14th Annual Nantucket Conference and had repeatedly been buttonholed to comment on the reports, she said.
Microsoft has more than $56bn (£30.8bn) in cash reserves, which has prompted some Wall Street analysts to call for the company to spend greater amounts on growth. A year ago, the software giant bought up a Romanian antivirus company, and the software powerhouse has said it will eventually offer a service to protect computers against viruses and other online threats.
Microsoft didn't comment on the rumoured buy, citing its policy of silence on speculation.
Network Associates has been fighting to grab greater share of the security market from its chief rival, Symantec, for many years. To make the company more competitive, executives committed to reducing its operating margin to 25 percent by the middle of next year.
Reports had also said that Network Associates would announce layoffs on 1 July. Keavney said the company's commitment to reduce operating margins does not involve layoffs, but she said the cost-cutting measure had not been ruled out completely.
Network Associates' stock price had risen 58 cents, or 3.5 percent, to $17.15 by midafternoon Tuesday.
