Apple has been ordered to pay a fine of $532.9m after a US judge found the iPhone maker's iTunes software infringed on patents owned by Smartflash LLC.
Texas-based Smartflash is a patent licensing firm with a portfolio of patents over technologies used in devices including smartphones, gaming consoles, smart TVs, set top boxes, netbooks and app stores.
The company was seeking $852m (£552m, €752m) from Apple in damages, after suing the iPhone maker in May 2013. It claimed the iTunes software infringed on its patents related to accessing and storing downloaded songs, videos and games.
The judge found that Apple wilfully used Smartflash's patents without permission.
"Smartflash is very happy with the jury's verdict, which recognizes Apple's longstanding willful infringement," Brad Caldwell, a lawyer for Smartflash, said in an email to Reuters.
Meanwhile, Apple said it would appeal the ruling, stressing that reforms are needed in the patent system to avoid litigations. The company earlier tried to throw out the lawsuit, but it failed in the attempt.
"Smartflash makes no products, has no employees, creates no jobs, has no U.S. presence, and is exploiting our patent system to seek royalties for technology Apple invented," Apple said in a statement.
"We refused to pay off this company for the ideas our employees spent years innovating and unfortunately we have been left with no choice but to take this fight up through the court system."
The case is Smartflash LLC, et al v. Apple Inc, et al, in the US District Court for the Eastern District of Texas, No. 13-cv-447.
Electronics Co Ltd, HTC Corp, Amazon and Google Inc are also facing patent infringement lawsuits filed by Smartflash, according to media reports.