The cost of the deal has not been released, but Sainsbury’s said it would end up with a 64% stake in Anobii.
Anobii has more than 600,000 users worldwide and offers 60,000 books.
Sainsbury’s said it was committed to becoming “a key player in the digital entertainment market”. In addition to selling e-books, Anobii offers users the chance to rate, review, share and discuss their choices with other members of the service.
Mike Bennett, Sainsbury’s head of digital entertainment, said such interaction on Anobii was “a clear differentiator” from its e-book retail rivals.