Microsoft Loses at Top Court on $300 Million Award

The U.S. Supreme Court upheld a patent-infringement verdict that may cost Microsoft Corp. (MSFT) $300 million and already has forced changes in its Word software.

The justices today unanimously rejected calls from Microsoft and its allies, including Apple Inc. (AAPL) and Google Inc. (GOOG), to make some patents more vulnerable to legal challenge.

The ruling is a victory for closely held I4i LP, which claimed in its 2007 lawsuit that its patented technology had been incorporated into Word, the word processing program used by 500 million people. Microsoft, which had $5.2 billion in profit in the first quarter of 2011, hasn’t yet paid i4I any damages.

The award is the largest ever upheld by an appeals court in a patent case.

The case is Microsoft v. I4i Limited Partnership, 10-290. (BLOOMBERG)