The U.S. International Trade Commission issued a preliminary ruling that found Motorola Mobility Holdings of infringing on one of the seven patents held by Microsoft Corp.

The ruling by an administrative judge still needs to be reviewed by a six-member commission which can choose to reverse the judge's decision. The Microsoft patent that Motorola was found to have violated covers scheduling events and synchronizing calendars from a mobile phone. The phones in question are the Motorola Droid 2, the Droid X and the Backflip.

Motorola portrayed the ruling as a victory for the company as the judge threw out six of the seven patents Microsoft had accused Motorola of violating in its original complaint.

"We are very pleased that the majority of the rulings were favorable to Motorola Mobility," said Scott Offer, senior vice president and general counsel of Motorola Mobility, in a prepared statement. "The ALJ's initial determination may provide clarity on the definition of the Microsoft 566 patent for which a violation was found and will help us avoid infringement of this patent in the U.S. market."

Microsoft for its part was also satisfied with the ruling. David Howard, corporate vice president and deputy general counsel at Microsoft said the company was pleased with the ruling and that Motorola should reach a patent licensing deal with Microsoft.

"As Samsung, HTC, Acer and other companies have recognized, respecting others' intellectual property through licensing is the right path forward," Howard said.

Microsoft could still force Motorola to make changes to its smartphones and tablets to avoid infringement violations on Microsoft's patent. The ruling could also aid Microsoft's strategy of charging for licensing fees from its competitors. The software giant already has licensing deals in place with several hardware companies that use Google's Android software including Samsung Electronics and HTC Corp. Motorola doesn't have a licensing deal with Microsoft.

Microsoft originally brought suit against Motorola over nine patents in October 2010. There are now 25 different patent suits in different courts around the world. Motorola has in turn sued Microsoft for violating 25 of Motorola's own patents.

The initial ITC ruling will now be reviewed by the full commission with a final decision expected in April 2012. The panel will also consider Microsoft's request that Motorola phones found infringing be banned from the market in the U.S.