Microsoft on Thursday lost its bid for an en banc appeal in a patent case against i4i.

The Federal Circuit Court of Appeals refused Microsoft's request to hear the case with a full panel of judges. The case stems from a battle over an XML editor in Word, which i4i said infringed on one of its patents.

"We're disappointed with the decision," Kevin Kutz, director of public affairs for Microsoft said in a statement. "As far as next steps, we continue to believe there are important matters of patent law that still need to be properly addressed, and we are considering our options for going forward."

Loudon Owen, chairman of Toronto-based i4i, said the company "is delighted by this ruling."