The proceeding in a Seattle federal court will determine how much of a royalty Microsoft Corp should pay Google Inc for a license to some of Motorola's patents. Google bought Motorola for $12.5 billion, partly for its library of communications patents.

If U.S. District Judge James Robart decides Google deserves only a small royalty, then its Motorola patents would be a weaker bargaining chip for Google to negotiate licensing deals with rivals.

Apple Inc and Microsoft have been litigating in courts around the world against Google and partners like Samsung Electronics Co Ltd, which use the Android operating system on their mobile devices.

Apple contends that Android is basically a copy of its iOS smartphone software, and Microsoft holds patents that it contends cover a number of Android features.

Motorola had sought up to $4 billion a year for its wireless and video patents, while Microsoft argues its rival deserves just over $1 million a year. A federal judge in Wisconsin last week threw out a similar case brought by Apple against Google just before trial.

During the run-up to trial in Seattle, both Microsoft and Google asked Robart to keep secret a range of financial details about the two companies, including licensing deals and sales revenue projections. Google requested that Robart clear the courtroom when witnesses discuss those details.

However, in an order on Monday, Robart rejected that request. The public will not be able to view the documents describing patent deals or company sales during trial, Robart ruled, but testimony will be in open court.

"If a witness discloses pertinent terms, rates or payments, such information will necessarily be made public," the judge wrote.

Additionally, any documents the judge relies on for his final opinion will be disclosed, Robart wrote on Monday.

Representatives for Microsoft and Google could not immediately comment on the ruling.

The case in U.S. District Court, Western District of Washington is Microsoft Corp. vs. Motorola Inc., 10-cv-1823.

(Reporting By Bill Rigby in Seattle and Dan Levine in San Francisco; editing by Jim Marshall)

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