Samsung Electronics Co. (005930), the world's top handset maker, fell the most in a week in Seoul trading after Apple Inc. (AAPL) won a court ruling blocking sales of the Galaxy Nexus smartphone in the U.S.
Samsung dropped as much as 2.4 percent to 1,172,000 won, headed for the biggest decline since June 25. The stock traded 1.9 percent lower as of 10:12 a.m., while the benchmark Kospi (KOSPI) index gained 0.2 percent.
The world's two biggest makers of high-end phones have accused each other of copying designs and technology and are fighting patent battles on four continents to retain their dominance in the $219 billion global smartphone market. Apple has sought to bar as many as 25 Samsung smartphones in addition to the Nexus model covered by the June 29 ruling, including the latest, the Galaxy S III.
"If this leads to a ban on the Galaxy S III, it could be a big problem for Samsung," Lee Sun Tae, a Seoul-based analyst at NH Investment & Securities Co., said by phone.
Sales of the Galaxy S III, the latest version in Samsung's best-selling smartphone series, started in the U.S. last month.
The ruling by U.S. District Judge Lucy Koh in San Jose, California, follows her June 26 order blocking U.S. sales of Samsung's Galaxy Tab 10.1 computer in the patent and trademark- infringement lawsuit over smartphones and tablets. On June 7, Koh expedited evidence sharing for Apple's bid to block sales of Samsung's Galaxy S III.