A US trade panel which hears patent infringement cases said it would undertake a wide-ranging review of its preliminary decision over whether Motorola Mobility violated Microsoft patents.
The International Trade Commission said Friday it would review portions of its judge's decision from December that Motorola Mobility infringed a Microsoft patent in making Android mobile phones.
In a complaint filed in October 2010 with the ITC, Microsoft accused Motorola Mobility of infringing nine patents for Windows Mobile and Windows Phone, which do everything from monitoring remaining memory to updating contact lists and synchronising on- and off-line use.
Two patents were dropped from the case during litigation. Motorola Mobility was found to infringe one patent out of the remaining seven.
A final decision is due later this year.
Microsoft said it looked forward to the review.
"We remain confident that the commission will affirm that Motorola has infringed our intellectual property," said David Howard, Microsoft's corporate vice president and deputy general counsel for litigation.
Motorola Mobility had no immediate comment.
The ITC is a popular venue for patent litigation since it has the power to forbid the importation of products which infringe patented technology.
Microsoft said in its complaint that the infringing devices included Android phones like the Motorola Droid 2, the Droid X, Cliq XT, Devour, Backflip and others, including the associated software.
The case at the ITC is No. 337-744.
(Reporting By Diane Bartz; Editing by Bernard Orr)