Ingram Book Group will handle single-book orders for Amazon.com when the online retailer does not have the book in its inventory, as part of a deal that the two firms signed recently.
The deal is expected to go into effect in the coming months. Amazon will pay Ingram an undisclosed amount of money for the fulfillment service.
The development comes after Amazon began managing online orders for offline rival Borders Books, which had a previous fulfillment relationship with Ingram.
The move by Amazon also continues a trend of farming out some of its operations. Amazon built a formidable fulfillment infrastructure that, since its debut in 1996, made it appear to be bent on operating solo.
Amazon last year began offering items such as prescription drugs and downloadable audio books via firms such as Drugstore.com and Audible.com.