NEW YORK -- Amazon has alerted its Kindle customers that they are entitled to a credit on prior electronic book purchases as part of settlements between some major e-book publishers and the government.

In September a federal judge approved the U.S. Justice Department's settlement with Hachette, HarperCollins and Simon & Schuster, which were accused of conspiring in a price-fixing scheme.

Amazon.com Inc. told its Kindle customers over the weekend that they will be contacted when the credit is applied to their account if the court approves the settlement in February. Customers don't need to do anything to receive the credit.

Credit for an as-yet undetermined amount will be given for every eligible Kindle book purchased between April 2010 and May 2012. The credit can be used to buy e-books or print books, or customers can request a check in the amount of the credit.