Amazon CEO Jeff Bezos. Michael Seto/Business Insider The contract between "Big Five" book publisher HarperCollins and Amazon is about to expire, and HarperCollins is refusing to sign an agreement with the new terms that Amazon is asking, a source with knowledge of the situation tells Business Insider.

The contract presented to HarperCollins was the same contract recently signed by Simon & Schuster, Hachette, and Macmillan, Amazon confirmed.

If HarperCollins and Amazon don't come to an agreement, no print or digital HarperCollins books will be available on Amazon once its existing contract runs out "very soon," our source says.

Last year, Amazon fought a brutal, public battle with Hachette after the publisher's contract expired in March. After a long back-and-forth, the two came to an agreement that reportedly gave Hachette "control over most of its pricing but offered incentives to sell at lower prices," while Amazon "got increased co-op funds, the payments for placement on the retailer's website." At the time, both Amazon and Hachette said they were "pleased with the agreement," and Simon & Schuster and Macmillan both signed a similar contracts (the status of Penguin's contract with Amazon is unknown).

A HarperCollins representative said the publisher does not comment on its contracts with retailers.

An Amazon representative sent the following:

"I can't comment on that rumor. I can say that we have offered Harper the same terms for a contract that Simon & Schuster, Hachette, and Macmillan have all recently agreed to."

In late 2013, HarperCollins formed a partnership with Accenture to sell e-books of "The Chronicles of Narnia" and other titles by C.S. Lewis on individual websites. In July 2014, it decided to start selling its own print and e-books directly through HarperCollins.com, cutting Amazon out of the equation for some sales.

At the time, Forbes contributor Jeremy Greenfield wrote that HarperCollins was "taking steps to build and strengthen alternate retail channels, grow in size, and create new business lines" so that it would not have to rely as much on Amazon. As the publisher and Amazon continue their negotiations, HarperCollins will most likely be relying on these alternate retail channels even more.