Microsoft wants the US Patent and Trademark Office to reject Apple's application for the name 'App Store', arguing that the term is generic and one the iPhone maker's competitors should also be able to use.
Yahoo reports that Apple's trademark application, which was filed in 2008, relates to goods and services including "retail store services featuring computer software provided via the internet and other computer and electronic communication networks".
In its motion, filed on Tuesday, Microsoft said: "'App store' is a generic name that Apple should not be permitted to usurp for its exclusive use. Competitors should be free to use 'app store' to identify their own stores and the services offered in conjunction with those stores."
While the term 'App Store' has become synonymous with Apple and its products, Microsoft and a number of other major players in the retail market also operate or are developing their own app stores.
Microsoft's Windows Phone 7 now plays home to 5,500 apps in its marketplace, more than 60 of which carry Xbox Live features.