The suit, filed on Tuesday in a federal court in San Diego, is the latest in struggle that has simmered over the past year over audio and video coding and other technologies patented by Lucent's research arm, Bell Laboratories.
The Wall Street Journal first reported this story on Friday, noting that Microsoft was seeking to invalidate 13 Lucent patents.
"We believe the suit is without merit, and we will continue to seek fair and reasonable compensation for the use of our intellectual property," said Mary Lou Ambrus, a Lucent spokeswoman.
Lucent had first filed suit against two Microsoft customers--Dell Computer in February and Gateway last June--alleging that the PC makers had infringed on several Bell Labs patents. Dell and Gateway then asked Microsoft to shield them from damages since the technologies in question appear to be within Microsoft's products.
The telecommunications equipment maker's cases against Dell and Gateway are ongoing.
Microsoft could not immediately be reached for comment.
A person close to the case noted that Lucent and Microsoft had been talking about a patent-licensing agreement and seemed surprised that the software giant had filed the suit.