Macmillan, a subsidiary of the German company Verlagsgruppe Georg von Holtzbrinck GmbH, was one of five publishing companies sued by the Justice Department for antitrust violations. In September, federal prosecutors settled with Hachette Book Group Inc., HarperCollins Publishers LLC, Penguin Group (USA) Inc. and Simon & Schuster Inc.
Apple Inc. was also named in the lawsuit. The case is scheduled to go to trial in June.
The Justice Department said the five publishers and Apple conspired to keep the price of e-books and their profit margins up with one executive referring to the "wretched $9.99 price point." Government lawyers said retail prices as a result were as high as $14.99 for the most popular books.
Macmillan agreed to end all discounting bans and not to agree to new ones before the end of 2014. It will also notify the Justice Department of any joint ventures in e-books with other publishers.