A federal judge has denied Apple's request to immediately stop Amazon from using the term "Appstore" to describe its digital downloads storefront.

In an 18-page opinion filed today with the U.S. District Court for Northern California, Judge Phyllis Hamilton denied Apple's request for a preliminary injunction preventing Amazon's use of the term, which Apple claims it has trademark rights to. As expected, Hamilton ruled that Apple had not established the likelihood of confusion between the competing brands, but she also said she did not agree with Amazon's contention that the mark is purely generic:

The court finds that Apple has not established a likelihood of success on its dilution claim. First, Apple has not established that its "App Store" mark is famous, in the sense of being "prominent" and "renowned." The evidence does show that Apple has spent a great deal of money on advertising and publicity, and has sold/provided/furnished a large number of apps from its AppStore, and the evidence also reflects actual recognition of the "App Store" mark. However, there is also evidence that the term "app store" is used by other companies as a descriptive term for a place to obtain software applications for mobile devices.

Apple representatives did not immediately respond to a request for comment.

Apple filed suit against Amazon in March, taking aim at the company's newly launched Appstore, which sells mobile applications to users on Google's Android platform. At the time, an Apple spokeswoman said, "we've asked Amazon not to copy the app store name because it will confuse and mislead customers."

Amazon responded in April by countersueing Apple, saying that "App Store" is too generic, and it wanted Apple's case dismissed. In a court filing last month, Apple fired back, saying that it "denies that the mark App Store is generic and, on that basis, denies that the Amazon Appstore for Android service is an 'app store.'"

An effort by Microsoft, HTC, Nokia, and Sony Ericsson in May sought to invalidate Apple's European trademarks, while Microsoft's taken on Apple's U.S. trademark application with the help of linguists.

Apple v. Amazon, Order Denying Motion for Preliminary Injunction