Hachette US, HarperCollins US and Simon & Schuster US have agreed to pay out a total of more than $69m (£43.5m) to resolve antitrust claims of unlawful e-book price-fixing.
The payment will be made to compensate consumers who bought e-books from them between April 1st 2010 and May 21st 2012. Payment will begin 30 days after court approval of the settlement becomes final.
The Connecticut attorney general George Jepsen, announcing the settlement alongside 54 attorneys general in other states, districts and US territories, said it was "restitution to customers who were harmed by this price-fixing scheme."
"While publishers are entitled to their profits, consumers are equally entitled to a fair and open marketplace," Jepsen said.
Varying sums will be given to different states, with Connecticut consumers set to receive up to $1.3m (£820,000).
The settling publishers have also agreed to terminate their existing agency agreements with retailers for the sale of e-books. Macmillan and Penguin also face price-fixing claims but have not settled in the case.
A spokesperson for HarperCollins US said: "HarperCollins did not violate antitrust laws but made a business decision to settle to avoid the expense and distraction of litigation."
Hachette US commented: "Hachette was not involved in a conspiracy to illegally fix the price of e-books, and we have made no admission of liability. However, faced with the prospect of lengthy and costly litigation with government plaintiffs with virtually unlimited resources, we decided that the costs, uncertainties, and distractions of this litigation would be too disruptive to our business. Our choice to join the settlement was critical to putting these disputes behind us and focusing our attention on the business of inspiring, developing, and distributing great books."
S&S US said: "We are pleased to put the matter behind us and moving forward, to continuing our work with authors and accounts to grow the market for books of all formats."
Penguin US, Macmillan US and Apple will defend themselves against price-fixing charges in court in June 2013.