Share story Inc. said it is “not optimistic” that a dispute with publisher Hachette Book Group will be resolved soon and defended its actions as “doing so on behalf of customers.”

The comments, which Amazon made in an online post, are the first extensive remarks by the world’s largest online retailer about its skirmish with Hachette over digital-book prices.

The spat, which came to light in the past week, has resulted in Amazon blocking pre-orders for some of the publisher’s forthcoming releases. Among the books caught in the dispute is “The Silkworm,” the new novel by J.K. Rowling, writing under the pseudonym Robert Galbraith.

“Negotiating for acceptable terms is an essential business practice that is critical to keeping service and value high for customers in the medium and long term,” Amazon said in its post.

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The dispute highlights the growth of the e-book market, over which Amazon and Hachette are negotiating. While physical book sales in the U.S. are projected to fall to $19.5 billion this year from $26 billion in 2010, e-book sales are anticipated to jump more than eightfold to $8.7 billion, according to Forrester Research. The growth is being spurred by the increasing consumer use of tablets and smartphones, through which people read e-books.

Seattle-based Amazon dominates e-book sales with 60 percent of the market, according to Forrester. The company also helped pioneer the e-book market with the introduction of the Kindle e- reading device in 2007.

Sophie Cottrell, a spokeswoman for Hachette, didn’t immediately respond to requests for comment outside of regular business hours. Sarah Gelman, a spokeswoman for Amazon, declined to comment.

In its post, Amazon said the dispute with Hachette affects only a “small percentage” of its merchandise and said it had offered to Hachette to fund 50 percent of an author pool to mitigate the impact on writer royalties.

Hachette, a New York-based unit of French publisher Hachette Livre, includes Grand Central Publishing, Hyperion Books and Little, Brown & Co. Hachette Livre is a subsidiary of Lagardere SCA.

In a statement on May 23, Hachette said it was doing everything in its power “to find a solution to this difficult situation, one that best serves our authors and their work, and that preserves our ability to survive and thrive as a strong and author-centric publishing company.”

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