U.S. District Judge Phyllis Hamilton said in a court document that Apple had not established "a likelihood of confusion" with Amazon's Appstore for Android, though she did partially side with Apple in noting that the "App Store" term is not purely generic, Reuters reported on Wednesday.
Also on Wednesday, Hamilton set a trial date of October 2012 for the case. She had previously warned Apple that its lack of evidence of actual customer confusion was a "stumbling block" to its efforts to prevent Amazon from using the mark.
Apple spokeswoman Kristin Huguet responded to the decision by reiterating the company's position that Amazon's application store will "confuse and mislead customers."
Prior to the launch of Amazon's store, Apple sued the online retailer in March for "improperly using" the App Store trademark with the online retailer's software developer program. Days later, Amazon went ahead and launched its "Appstore for Android" in spite of the suit.
Subsequent filings from Apple have described Amazon's digital storefront as "inferior" and a "security threat" because it provided software for rooted Android phones, which are more vulnerable to security breaches.
Apple's "App Store" trademark has been hotly contested, with long-time rival Microsoft remaining one of its most vocal opponents. Earlier this year, the Redmond, Wash., software giant filed an objection to Apple's trademark filing on the grounds that "app" and "store" are generic terms. Apple countered by noting that Microsoft should know a thing or two about trademark terms since it had faced a "decades-long genericness challenge" to the Windows trademark.