The takeover, that is subject to regulatory approvals, is expected to be completed in the final quarter of 2008.
AbeBooks, who will fill a niche market for Amazon, represent 13,000 booksellers worldwide and an estimated 70 per cent of all antiquarian book sales on the internet take place through their websites.
This is the second ownership change for the Canadian company since it began operations in 1996. Five years ago, German company Hubert Burda Media bought a majority share.
However, the might of Amazon.com will doubtless raise concerns among those users who already believe AbeBooks had previously wielded too much power in the market.
In April 2006 members of the Antiquarian Booksellers Association, the Antiquarian Booksellers Association of America and Biblion organized a two-day boycott of AbeBooks over its decision to charge a 5.5 per cent fee for processing all Mastercard and Visa transactions, on top of the eight per cent sales commission.