A consortium of 13 companies, including bookstore chain Kinokuniya Co. and online shopping mall Rakuten Inc., will test sales of e-books at regular bookstores next spring, sources said Sunday.

The aim is to familiarize consumers with e-books and to halt the decline of regular bookstores across the country, they said.

The consortium is also aiming to counter U.S. online retail giant Amazon.com Inc., which has held the largest share in Japan's e-book market since the launch of its Kindle tablets.

The consortium is considering showing a list of e-books at bookstores and having buyers download the titles, the sources said.