A U.S. judge has ordered a new trial to determine how much Samsung Electronics should pay Apple for copying the look of the iPhone.

U.S. District Judge Lucy Koh in San Jose, California issued an order late on Sunday, 10 months after the U.S. Supreme Court set aside a $399 million award against Samsung for mimicking the iPhone's look for its Galaxy and other devices.

The Supreme Court said damages could be based only on parts of a device that may have infringed patents, not necessarily the entire device.

Koh said the jury instructions at the Apple-Samsung trial "did not accurately reflect the law" and may have prejudiced Samsung by preventing jurors from considering whether any infringement covered "something other than the entire phone."

The $399 million is part of a $548 million payment that Samsung made to Apple in December 2015.

Samsung welcomed Koh's order.

"We welcome to District Court's decision for a new trial. This is a historic opportunity to determine how the U.S. Supreme Court's guidance on design patent damages will be implemented in our case and future cases," Samsung said.