Apple won a UK lawsuit filed by Samsung as part of the two companies' global patent battle over technology used on mobile devices.
Judge Christopher Floyd in London invalidated the Korean company's patents for technology allowing phones to send and receive information over third-generation mobile networks.
Samsung argued at two separate trials last year that Cupertino, California-based Apple had infringed three patents.
The iPhone maker said the patents were invalid and, regardless, Samsung was required to license the technology under fair terms if it's vital for connecting to modern networks, according to court filings.
Samsung and Apple have each tallied victories in patent disputes fought over four continents since the iPad maker accused Asia's biggest electronics producer in April 2011 of ''slavishly copying'' its devices.
''It just marks another step in their global patent war,'' said Gary Moss, a lawyer at EIP Partnership who isn't involved in the case. ''Samsung doesn't seem to have had much luck so far.''
Nam Ki Yung, a spokesman at Suwon, South Korea-based Samsung, said in an email the company was disappointed by the UK ruling and would review the judgment before deciding whether to appeal.
IP rights
''For decades, we have heavily invested in pioneering the development of technological innovations in the mobile industry,'' Samsung said in a statement. ''We will continue to take the measures necessary to protect our intellectual property rights.''
Apple spokesman Alan Hely declined to comment on today's ruling.
While Apple settled its lawsuits with HTC. in November, the company continues to wrestle with Samsung for dominance in the international mobile phone market.
At stake is market share in the mobile-device market that researcher Yankee Group expects to double to $US847 billion by 2016.
Samsung said this week it would ask for a further review of patent damages awarded to Apple following a US judge reducing by nearly half a $US1.05 billion award to the company, after determining the jury based its decision at trial on an incorrect legal theory.
Apple lost an October UK appeal ruling over whether Samsung's Galaxy tablets infringed the design of the iPad, upholding a decision by a lower court that found several of Samsung's tablets weren't ''cool'' enough to be confused with the iPad.