WASHINGTON (Reuters) - The U.S. Justice Department will close its investigation into Samsung Electronics' use of a special class of essential patents to attack rivals but said it would continue to monitor related patent litigation.
Samsung had filed a patent infringement complaint against Apple Inc. at the U.S. International Trade Commission and won an order in June 2013 banning the sale of some older iPhones and iPads in the United States.
One of the patents involved in the case was a so-called standard essential patent (SAP), a key class of patents that ensure different devices can work together, and are expected to be widely licensed.
The Justice Department and the U.S. Patent and Trademark Office have both argued that sales bans imposed as punishments for infringing on these patents should be done only in very rare cases.
The ITC's sales ban was overturned in August by the Obama administration. Based on that action, a Justice Department investigation was unnecessary, the department said on Friday.
"The Antitrust Division has determined that no further action is required at this time," the division said in a statement.
Apple, which revolutionized the smartphone, and Samsung, which makes mobile phones based on Google's Android software, have been battling each other in courts in more than 10 countries. Samsung and Apple are the No. 1 and No. 2 smartphone makers, globally.
Apple shares were up 1.76 percent at $521.57 per share in midday trading, holding onto earlier gains.
(Reporting by Diane Bartz; Editing by Ros Krasny, Eric Beech and Bill Trott)