The European Patent Office (EPO) has ruled that a key patent allegedly being infringed by Nokia and HTC is not valid, alleviating fears that the two device-makers’ products could be banned in Germany.

The ruling follows some earlier legal successes for the patent’s owner, IPCom, in a long running dispute between the parties following Nokia and HTC’s decisions not to strike licensing deals with the German firm.

"Today's judgment does not impact the successful rulings regarding infringement proceeding against Nokia and HTC in Germany and UK," said IPCom, which is expected to appeal the EPO’s ruling.

"IPCom needs to recognise its position and end its unrealistic demands for what remains of this significantly diminished portfolio," countered Nokia’s IP VP Paul Melin.

"This ruling undermines IPCom's license infringement claim against us,” added HTC. “We trust IPCom will now reconsider its opportunistic dispute with HTC and withdraw its legal action against us.”

The key patent in question is known as 100A, which is related to the ability to assign priority levels to calls made over a mobile network. It is believed to have been declared standards-essential, meaning that IPCom has to licence it on fair, reasonable and non-discriminatory (FRAND) terms.

IPCom owns a portfolio 160 patent families originally developed by Bosch for in-car systems.