HELSINKI/LONDON, Dec 21 (Reuters) - Nokia (NOK1V.HE: Quote, Profile , Research) and wireless technology firm InterDigital (IDCC.O: Quote, Profile , Research) each declared victory in a court decision on Friday over patents related to the UMTS third-generation (3G) mobile phone standard.

A London High Court ruled in favor of Nokia, the world's largest mobile-phone maker, that most of the patents in the case are not essential for mobile phone operators wishing to comply with the 3G standard, as claimed by InterDigital.

The court did rule that one patent relating to power control in mobile handsets was essential to the 3G standard. The validity of that patent may be considered at a later hearing and Nokia could be found to have infringed it.

Shares of InterDigital rose $2.32, or 11.41 percent, to $22.66 on the Nasdaq after the ruling. Nokia shares closed up 4 percent in European trade.

Both sides said they were happy about the court's ruling regarding patents related to power controls that increase capacity of mobile base stations and improve signal quality.

"The result is an extremely favourable outcome for Nokia and other industry participants," Nokia said in a statement.

InterDigital said in a statement it was pleased with the outcome and that they believe this is the first ruling by any court of law finding any patent to be essential to the 3G standard.