Microsoft has been dealt a blow by the US International Trade Commission (ITC), which says Alcatel-Lucent has not violated patents related to unified communications.
The ITC had previously ruled that Alcatel-Lucent was guilty of infringing on one of four Microsoft patents included in the lawsuit, but overturned that decision in a ruling on Monday, deciding that many of the contested patent claims were invalid.
Unified communications refers to the combination of communications services including fixed and mobile telephony, instant messaging, videoconferencing, and presence services.
This ruling is just the latest instalment in a long running patent battle between the two companies. Lately Alcatel-Lucent has been on a winning streak.
In April, a jury in San Diego ordered Microsoft to pay Alcatel-Lucent $367.4 million for infringing on two patents related to user interface technology.
Alcatel-Lucent is now happy to rack up another victory. "We are pleased with the ITC's decision," said spokesman Stéphane Lapeyrade.
Microsoft is, as can be expected, not pleased with the verdict. It is disappointed that the ITC reversed the earlier victory, according to spokesman David Bowermaster. The company is waiting for the ITC's detailed ruling so it can understand the reasoning, he said.