A US appeals court Thursday lifted a sales ban on Google-branded Samsung smartphones in a patent fight with Apple, saying there was no evidence sales were driven by features copied from the iPhone.

The appeals court in Washington overturned an injunction issued by a judge in California for the Galaxy Nexus phone as part of the lengthy patent case, saying the lower court "abused its discretion."

Judge Lucy Koh issued the injunction June 29, before a landmark jury ruling which found Samsung illegally copied features from Apple's iconic iPhone.

She ordered the temporary ban, saying that Apple "has shown a likelihood of establishing both infringement and validity" of its patents related to the iPhone's Siri virtual assistant software.

But the appeals court said Apple must show not only that it would suffer "irreparable harm" but "establish that the harm is sufficiently related to the infringement."

"In other words, it may very well be that the accused product would sell almost as well without incorporating the patented feature," the court said in an 18-page opinion.

"And in that case, even if the competitive injury that results from selling the accused device is substantial, the harm that flows from the alleged infringement... is not."

The appeals court in July issued a "stay" on the injunction, which allowed sales to continue while arguments were heard.

The appellate panel noted that even though Apple had claimed Samsung infringed on patents from Siri voice assistant, the Nexus phones lacked a similar feature.

"Galaxy Nexus does not have a feature equivalent to Siri," the appeals court said, while noting that Apple argues "that the functionality of Siri depends in part on unified search," which relates to its patent.

The opinion said Judge Koh "erred" in interpreting the law and that Apple failed to show "that consumers buy the Galaxy Nexus because it is equipped with the apparatus claimed in the '604 patent – not because it can search in general, and not even because it has unified search."

Samsung welcomed Thursday's development.

"Today's decision confirms that the role of patent law is to protect innovation and not to unreasonably stifle competition and restrict consumer choice," it said in a statement.

"We will continue to take all appropriate measures to ensure the availability of our innovative products."

Galaxy Nexus launched in the United States in April, among many smartphones using Google's Android mobile platform.

The latest ruling is only one part of a massive patent case involving the US and South Korean electronics giants.

Apple, which won a jury award of more than US$1 billion for patent infringement, is seeking to ban various Samsung phones and tablets on the basis of that verdict.

Apple has asked the court to ban some of the newer 4G phones from Samsung's Galaxy line and other smartphones from the South Korean firm.