The US Supreme Court has upheld a $290 million patent-infringement verdict against Microsoft, ruling that software giant infringed patents held by small Canadian company, i4i.
The ruling also scuppers Microsoft's hope of making it harder for companies to sue it for patent infringement by tweaking the law.
The outfit wasn't happy that it had been told by a lower court to fork out $290 million to i4i which had accused Microsoft of infringing patents it holds relating to document editing. The judgement also forced Microsoft to stop selling some versions of its word processing package Word.
A miffed Microsoft complained to the Supremes and sought the change to the way patents could be invalidated. It preferred the wording a "preponderance of the evidence", but the law-makers dug their heels in and stuck with "clear and convincing evidence" and agreed Microsoft should hand over the cash.
In a statement, Microsoft claimed the case "raised an important issue of law which the Supreme Court itself had questioned in an earlier decision and which we believed needed resolution.
"While the outcome is not what we had hoped for, we will continue to advocate for changes to the law that will prevent abuse of the patent system and protect inventors who hold patents representing true innovation."
The Supreme Court unanimously sided with i4i and said a challenge to a patent claim "requires an invalidity defense to be proved by clear and convincing evidence." Justice Sonia Sotomayor, writing the main opinion, said that Congress set the standard in a 1952 patent law and that any "calibration of the standard of proof remains in its hands."
The likes of Google and Verizon Communications were in Microsoft's corner, seeking a ruling that they hoped would make it harder for patent holders to sue technology companies.
Inventors and drug companies were backing i4i claiming any change would harm inventors.