Qualcomm beats Apple in $31m patent infringement case

US smartphone chip titan Qualcomm said Friday it won a $31 million verdict in its multifront war with Apple over patented technology used in iPhones.

A jury in a federal court in Southern California ordered that Apple pay Qualcomm for patent infringement for chips used on iPhone 7, 8 and X models.

The damages were tabulated from 6 July 2017 through the end of the trial, according to a Qualcomm statement.

"Today's unanimous jury verdict is the latest victory in our worldwide patent litigation directed at holding Apple accountable for using our valuable technologies without paying for them," Qualcomm general counsel Don Rosenberg said in a release announcing the verdict.

Qualcomm shares closed the formal trading day up 2.2 per cent to $56.60.

Patents at issue in the case involved "flashless booting" that allows devices to connect quickly to the internet after being turned on and technology that lets smartphone apps move online data efficiently.

A third patent related to promoting rich graphics in games while protecting battery life, according to Qualcomm.

On another front in the complex legal battle between two US companies a federal judge in Southern California on Thursday issued a preliminary ruling that Qualcomm owes Apple nearly a billion dollars in patent royalty rebate payments the chip maker is withholding, according to US media reports.

Apple sued Qualcomm two years ago over the payments, which were part of a contracted arrangement. The judge's decision will be on pause until after a trial in the case.

Apple did not immediately respond to a request for comment.

Qualcomm late last year escalated a legal war with Apple, accusing the iPhone maker of stealing secrets and sharing them with mobile chip rival Intel, according to court documents.

Apple's goal was to buy mobile chips from Intel instead of depending on Qualcomm, the dominant maker of mobile phone processors and has argued that Qualcomm abuse of its dominant position was harmful to the whole industry.

Apple's ongoing legal battle with Qualcomm includes accusations that the chipmaker has been charging for invalid patents and claiming the chipmaker was seeking a disproportionate amount for a single component.

The two California tech giants have been locked in a long-running battle over patents and royalties that has played out in courts and administrative bodies worldwide.