Washington: InterDigital Inc , a patent licensing firm, lost an infringement fight over wireless phone technology on Wednesday, as a U.S. appeals court ruled against it.
InterDigital had sued phone maker Nokia and ZTE Corp over patents used in the phones. Since the suit was filed, Nokia`s handset business was purchased by Microsoft Corp .
InterDigital shares slid, closing down 3.4 percent at $49.14.
The U.S. Court of Appeals for the Federal Circuit upheld a decision by the International Trade Commission, which found the patents were not infringed.
The appeal involved five patents. Four help the cell phone use less power and one allows the device to use various networks to transfer data.
The Federal Circuit also upheld the ITC`s decision to declare the fifth patent invalid because it is obvious, which means it cannot be infringed.
Microsoft was pleased with the decision, said spokesman David Cuddy.
ZTE said it was confident all along that it was innocent of infringement. "ZTE is pleased that the Court of Appeals has confirmed this," the company said in a statement.
InterDigital said it was disappointed by the decision but would push on with other litigation that it already has under way.
"We remain very confident in the strength of our portfolio, and in our ability to continue to grow our licensing program," William J. Merritt, chief executive of InterDigital, said in a statement.
Separately, InterDigital sued ZTE Corp and Microsoft`s Nokia handset business in a district court in Delaware using different patents. It won against ZTE in October but the Microsoft trial has not yet begun.
Companies frequently sue at the ITC to win an injunction against infringement and in district court to win damages.
The case at the International Trade Commission is InterDigital Communications v. Nokia Corp and ZTE Corp and is No. 337-868. At the Federal Circuit, it was No. 2014-1176.
