Amazon.com Inc., responding to a trademark lawsuit by Apple Inc. over its use of the words “App Store,” said the term is generic and denied that the iPhone maker has exclusive rights to the phrase.

Amazon, the world’s largest online retailer, said it isn’t required to obtain a license or authorization to use “App Store” because the term is “unprotectable” and won’t be confused or unfairly compete with Apple’s App Store service, according to a filing yesterday in federal court in Oakland, California. Amazon’s Appstore offering downloads of software for Android devices opened March 22. App is short for application.

“Based on their common meaning, the words ‘app store’ together denote a store for apps, such as the app stores operated by Amazon and Apple,” Amazon said in the filing.

Apple’s lawsuit, filed March 18, should be thrown out and a court order confirming Amazon’s right to use the words should be issued, Seattle-based Amazon said.

Kristin Huguet, an Apple spokeswoman, didn’t immediately return a voice-mail message seeking comment.

Apple’s App Store, started in 2008, offers downloads of programs from the company and third-party developers to users of iPhones, iPod media players and iPad tablet computers.

Apple, based in Cupertino, California, applied to register App Store as a trademark in the U.S., and the U.S. Patent and Trademark Office approved the application, Apple said in the lawsuit.

The case is Apple Inc. v. Amazon.com Inc., 11-1327, U.S. District Court, Northern District of California (Oakland).