Creative Technology, a Singapore-based consumer electronics group, has filed patent complaints against Apple and is seeking to halt the import and sale of iPods in the US.
Creative had previously threatened to sue Apple for alleged infringements after the Singapore company received a patent for its Zen music player last year.
Shares of Apple fell 2.6 per cent on Tuesday to $66.05 as concerns that the lawsuit could force Apple to halt US iPod sales were tempered by a US Supreme Court ruling on Monday that could make it more difficult for plaintiffs in intellectual property cases to win injunctions against companies alleged to have violated patents.
The filings come after Creative recently reported a record quarterly loss of $114m, for which it blamed falling prices in the digital player market and unsold inventory.
Apple is the market leader for MP3 players, while Creative has a share of less than 10 per cent in the US market. IPods accounted for about 40 per cent of Apple?s $4.4bn in sales last quarter.
Creative alleged that Apple iPod devices use software menus similar to those on Creative?s Zen and Nomad brands that allow users to find and play back music.
The company is seeking an injunction and increased damages for Apple?s ?wilful infringement of the Zen patent?, which was filed initially in 2001.
It also filed a complaint with the US International Trade Commission asking the agency to determine whether Apple had violated trade laws by selling iPod and iPod Nano music players, imported from China, because of the alleged patent infringements.
Creative asked for an exclusion order and cease-and-desist order against Apple that would prohibit it from selling, marketing or importing iPods in the US.
Apple did not return calls seeking comment on Tuesday.
The lawsuit is the latest in a series of legal challenges to Apple?s iPod franchise. The French parliament last week drew closer to approving a law that would require Apple to make songs on its popular iTunes online music store compatible on music players other than the iPod.
Apple also recently fought off a lawsuit in the UK by Apple Corps, the Beatles? record label, which had sought to stop Apple using the Apple name in connection with the iTunes service.
Additional reporting by Kevin Allison in San Francisco