Judge James Ware of the US District Court for the Northern District of California, dismissed three claims brought by aggrieved iPod owner Thomas Slattery earlier this month; but he allowed others to survive Apple's challenge.
Slattery complains that he was forced to buy an iPod to listen to his iTunes purchases on the move.
The Digital Rights Management (DRM) software of the iTunes music store allows songs to play on iPods, PCs, or to be burned to CD for playing on a home stereo or personal CD player. But iTunes tracks are not compatible with rival MP3 players like Sony's new Walkman.
Slattery sued in January, accusing Apple of unlawfully bundling, tying and/or leveraging its monopoly in the market for the sale of legal online digital music recordings "to thwart competition in the separate market for portable hard drive digital music players, and vice-versa."
According to AppleInsider, the surviving claims include allegations that Apple possesses monopoly power and has coerced customers into purchasing both iPods and iTunes files.
A similar argument was dismissed by the French Competition Council in November.
That case followed a complaint from the French division of internet retailer Virgin Mega alleging that Apple acted anti-competitively in failing to license the DRM software in its iPod.
Basing its reasoning on principles of European competition law, the Competition Council said that access to Apple's DRM software was not essential in order to support the development of the on-line download market.