Amazon is spending a total of $645 million for the three privately held companies. An announcement concerning the deals, expected to close by June 30, is expected later today.
Exchange.com operates the popular Bibliofind.com, a seller of used and antiquarian books, as well as Musicfile.com, which features music memorabilia and rare recordings. Amazon said this will add more than 12 million book and music items for sale.
Alexa Internet offers a free advertising-supported Web navigation service.
Accept.com is an e-commerce company developing technology for business and consumer transactions on the Internet.