Microsoft said the claim was without merit and that its actions are "proper and fully consistent" with a contract it signed with Veritas Software, which Symantec acquired last year.
The dispute centers on software technology that allows an operating system to store and manipulate large amounts of data and recreate files after a disk storage failure. Symantec claims Microsoft violated terms of a 2004 contract, under which Microsoft licensed this type of software from Veritas, by using it to develop competing products. Symantec said technology in Microsoft's upcoming Windows Vista operating system, due next year, misappropriates trade secrets found in its Volume Manager product, which it gained when it bought Veritas. Symantec went to court to stop Microsoft from developing or distributing Vista until Microsoft removes the intellectual property.
Microsoft in its statement said it had "worked hard" to resolve the dispute with Symantec and has "gone to great lengths" to ensure that its volume management technology works "side by side" with Symantec's.
Symantec and Microsoft have become sharper competitors of late, as Microsoft acquires and builds more network security functions into its products.
The lawsuit comes amid a charged atmosphere for intellectual property litigation. A Supreme Court ruling this week in favor of online auction company eBay in a patent infringement case could make it more difficult for litigants in intellectual property cases in the technology industry to gain injunctions to block distribution of other companies' competing products. In addition, a New Zealand actor moved the U.S. Patent and Trademark Office to reconsider the patent it granted to Amazon.com for its one-click shopping feature.