HTC sued Nokia, trying to get the patent declared invalid in the U.K. as a defensive tactic, but failed to achieve this when Sir Richard David Arnold, the judge in charge of the patents court of the England and Wales High Court ruled Wednesday that the patent is valid and was infringed by HTC. The patent describes a "modulator structure for a transmitter and a mobile station."

HTC will appeal the ruling immediately, an HTC spokesman said in an emailed statement.

The ruling is a significant development in Nokia's dispute with HTC, said Nokia spo
ckesman Mark Durrant in an email.

"Nokia will now seek an injunction against the import and sale of infringing HTC products in the U.K. as well as financial compensation," he said, adding that lawsuits have been filed against HTC over the same patent in Germany, Italy, Japan and the U.S. Nokia has also sued HTC in France and the Netherlands over other patents.

The patent in this case is one of 50 that Nokia has been asserting against HTC since 2012 when it started targeting HTC for what it calls unauthorized use of proprietary innovations.

This is the third court this year that has found HTC infringed Nokia, bringing the number of patents found infringed to four, Durrant said.

The U.S. International Trade Commission ruled in September that HTC infringed two patents held by Nokia related to cellphones and tablets. In March, Nokia won an injunction against the sale of some HTC handsets in Germany that infringe on a power-saving technology for mobile phones.