Apple has been ordered to pay the University of Wisconsin-Madison's patent licensing arm a sum of $506m (£387.49m). The company was sued for making use of a 'predictor circuit' developed by the Wisconsin Alumni Research Foundation (WARF).

The verdict was handed by US District Judge William Conley in Madison. He added $272m to the $234m jury verdict that WARF won in October 2015 against the iPhone maker.

The company allegedly continued to infringe upon the patent until it expired in December 2016 without paying what they owed WARF due to which the amount payable was increased.

However, Apple would be contesting the verdict, Reuters reports.

The University of Wisconsin-Madison first filed the case against the tech giant in 2014 when the university found that they were using a version of their 'predictor circuit'. Its function within a processor is to increase performance and speed by predicting the actions of the user before a command is given to the system.

The patent, awarded in 1998, was held by professor Gurindar Sohi and three of his students.

Apple, during the trial before a jury, reportedly argued that the patent was not valid and called for a Trademark Office review of the patent's validity. This was rejected by the office.

WARF filed a different lawsuit against Apple in 2015, alleging that chips in the later versions of the iPhone also infringed the same patent, but Judge Conley has set that case aside saying that there will be no ruling in the 2015 case until the company has had the chance to appeal against the first verdict.