Microsoft has been fined $200 million for patent infringement by verdict of a US jury.
The world’s largest software developer was ordered to pay the fine to Canadian software firm i4i.
The fine, issued by a federal jury in Texas, is the fourth largest jury verdict in the US and the second-largest patent jury award.
Microsoft denies the charge, and plans to appeal against the jury’s verdict.
“The evidence clearly demonstrated that we do not infringe and that the i4i patent is invalid,” a Microsoft spokesperson said.
“We believe this award of damages is legally and factually unsupported, so we will ask the court to overturn the verdict,” he added.
Last month Microsoft was ordered to pay $388 million for a patent infringement against anti-piracy software maker Uniloc Inc.
Early next month Microsoft faces a hearing with the EU that will decide whether its bundling of Internet Explorer with Windows is harming competition.