Amazon appears to be testing a new e-book and audiobook subscription service it’s calling “Kindle Unlimited,” which brings unlimited access to 600,000 e-books and thousand sof audiobooks for a fee of $9.99 per month. According to information discovered by users on the KBoards Kindle forum, the Kindle Unlimited service will be available on all devices, including the iPhone and the iPad likely via Amazon’s Kindle app. Amazon has pulled the pages that were found this morning but information on the service can still be seen through Google Cache and a single test page.

The now defunct Kindle Unlimited section Amazon lists several popular e-book titles, including Life of Pi, Water for Elephants and the entire series of Harry Potter and Hunger Games books. The titles appear to mirror many of those available thoruhg Amazon’s existing Kindle Owners’ Lending Library, a service that allows Kindle-owning Amazon Prime subscribes to rent free e-books.

There are several existing e-book subscription services such as those from Oyster and Scribd but Amazon has a larger catalog of books to offer, advertising more than 600,000 titles compared to Oyster’s 500,000 and Scribd’s 400,000 plus more than 7,000 audiobooks. So far, Kindle Unlimited appears to include books from publishers like Open Road Media, Workman, Algonquin, Bloomsbury, and Houghton Mifflin Harcourt. As of right now, its unknown when Amazon might officially launch its Kindle Unlimited subscription service and thus far, it hasn’t been made a statement regarding the test pages.

Source: KBoards via GigaOm