HarperCollins has signed a deal with Amazon to sell its books, much like the contracts the online bookseller has reached with other publishers.

Relations between Amazon and the New York publishers, always rather fraught, worsened last year when the bookseller and the publisher Hachette had a multimonth conflict over the price of e-books.

Amazon discouraged sales of Hachette books to pressure the publisher, and Hachette’s writers and their allies took to the barricades. The impasse was broken when Amazon signed a contract with Simon & Schuster in October and then used the same terms to broker peace with Hachette. A deal with another major house, Macmillan, promptly followed.

All the agreements allow the publishers to set their own e-book prices, a major point of contention, but give them financial encouragement to price cheaply.