Toronto-based i4i first sued Microsoft in 2007 over patent related to MS Word
Microsoft has lost its final appeal against a ruling by a lower court that it must pay Canada-based i4i $290m (£177m) over a patent dispute related to MS Word.
The US Supreme Court has ordered Microsoft to must pay the fine after lower courts had found that the company had infringed a patent on a technology linked to the 2003 and 2007 versions of MS Word.
i4i had first sued Microsoft fin 2007. The Toronto based company claimed that the technology behind MS Word belonged to it.
A Texan court ordered Microsoft to stop selling the 2003 and 2007 versions of Word. Microsoft had appealed citing use of the "clear and convincing" evidence standard instructed by the original judge as the wrong standard. Microsoft appealed that the decision should be based on a "preponderance" of evidence.
However, the Supreme Court upheld the lower court’s standard, saying that the "clear and convincing" standard was the correct one. The jury also dismissed Microsoft’s argument that the patent was invalid.
i4i chairman Loudon Owen said, "Microsoft tried to gut the value of patents by introducing a lower standard for invalidating patents. It is now 100pc clear that you can only invalidate a patent based on ‘clear and convincing’ evidence."
"This is one of the most significant business cases the court has decided in decades," Owen added.
Microsoft said, "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."