E-reader dark horse Kobo has a new master: Japanese mega-retailer Rakuten. The company bought the e-reader manufacturer for $315 million, with most of it going to majority shareholder Indigo Books & Music, from Canada. The backing of a powerful retailer should help the relatively small company compete better with the likes of Barnes & Noble and Amazon in the e-reader/tablet marketplace. Like its competitors, Kobo sells ebooks on Android, iOS and its own line of e-readers.

Kobo will continue to operate out of Toronto under the current CEO, Michael Serbinis. The 50 million quoted Kobo users will be added to Rakuten’s 72 million shoppers for a formidable media presence. The backing of suck a large firm should help Kobo secure even better deals for books and periodicals, maybe even expand into music and movies to compete with Amazon on all fronts.

Kobo’s latest e-reader, the full-color Kobo Vox, competes directly with the Kindle Fire, Nook Color and Nook Tablet. The 7-inch IPS tablet runs a modified version of Android Gingerbread with built-in access to Kobo’s bookstore and a selection of curated apps. The Vox is available right now (unlike the Fire and Nook Tablet) for $199. Though Kobo is a distant third in the e-book space, it should begin some aggressive expansion under new ownership – the tablet reader race just got even more interesting.

[via SlashGear]