Authors United, a loosely knit group of authors who banded together last year to apply pressure to Amazon during its then-dispute with Hachette, has called on its members to sign a new letter destined for the antitrust division of the Department of Justice.

Last fall Douglas Preston, the thriller writer who formed Authors United, aired his group's concerns about Amazon's domination of the retail book market in a meeting with the DoJ. Now, although the Hachette-Amazon disputed has ended, he said enough has not been done about Amazon's position in the marketplace.

In an e-mail sent Monday afternoon, calling on authors to sign the new letter, Preston wrote: “The settlement of the dispute did not change the fundamental problem: That one corporation now dominates the book market in the United States. We believe Amazon has used its power in ways that harm the interests of authors, readers, booksellers, and the publishing industry as a whole.”

Preston composed the letter to the DoJ, which will be sent days after Amazon celebrates its 20th anniversary, with the Authors Guild. The letter has also been endorsed by the American Booksellers Association and the Association of Authors’ Representatives.

“Today a single company, Amazon, has gained unprecedented power over America’s market for books,” it begins. “We are not experts in antitrust law, and this letter is not a legal brief. But we are authors with a deep, collective experience in this field, and we agree with the authorities in economics and law who have asserted that Amazon’s dominant position makes it a monopoly as a seller of books and a monopsony as a buyer of books.”

On Monday, ABA CEO Oren Teicher and ABA president Betsy Burton, owner of The King’s English Bookshop in Salt Lake City, sent a letter of their own to the DoJ. They wrote: “As with our author colleagues, we are concerned that the mega-book-retailer has achieved such considerable market power with such questionable business tactics that it is undermining the ecosystem of the entire book industry.”

Acknowledging letters can only go so far, Teicher said he’s hopeful that the DoJ will take notice. He said the "deleterious impact Amazon has had on consumers has become more apparent." And, while antitrust laws in the U.S. are different from those in other countries, "the fact that the European Union has launched its own investigation may give our DoJ reason to take another look." Lastly, he said, "the fact that authors, agents, and booksellers, who together know a bit about how our business operates, have joined together in making this request,” should make an impact.

For his part Preston believes the DoJ will respond. “Although, if it initiates an investigation, it obviously will keep that quiet," he said. "I believe the first amendment argument is powerful, simple, and correct: never in American history has a single corporation been allowed to monopolize a vital marketplace of information. This issue isn’t about authors, or publishers, or even the publishing ecosystem---it is about the free and unfettered flow of ideas in our society, something vital for our democracy. Even if Amazon was a benign corporation, this would be a problem.”