Amazon.com (NSDQ: AMZN) has bought Canada-based online used books site AbeBooks. No financial terms were disclosed in the announcement. Interestingly, AbeBooks will continue to function as a stand-alone operation. Amazon already had a reseller agreement with the site.

Abebooks says it has over 110 million used, rare and out-of-print books listed for sale by thousands of independent booksellers from around the world…it was launched in 1996, around the same time Amazon was launched. It acquired Germany’s JustBooks GmbH online book marketplace in 2001, which helped the company expand into the German, French and British online bookselling markets. In 2004, AbeBooks expanded its model to include new books, and acquired the Spanish company IberLibro, to better serve Spanish language markets. In 2002, the founding partners were bought out by German media company Hubert Burda Media. For more history, see this Wikipedia entry. More details in release.

Updated: Abebooks owns a 40 percent stake in books social net LibraryThing, which means that after the deal goes through, Amazon will become a minority investor in the company…LT’s founder blogs about this here. Amazon is already an investor in rival books social net Shelfari.

Techvibes did some back of the envelop calculations, and estimated that the acquisition price was in the $90 million to $120 million range.