Amazon.com has threatened to stop directly selling the books of some publishers online unless they agree to a detailed list of concessions regarding the sale of electronic books, according to two industry executives with direct knowledge of the discussions, according to the “New York Times” (http://www.nytimes.com/2010/03/18/technology/internet/18amazon.html?ref=technology).

The company is pressuring publishers just as Apple is also preparing to sell digital books for reading on its iPad, the article adds. Five of the country’s six largest publishers — Macmillan, Simon & Schuster, Hachette, HarperCollins and Penguin — have already reached deals with Apple to sell their books through its iBookstore, which will be featured on the iPad. (The holdout is Random House.)

Under those agreements, the publishers will set consumer prices for each book, and Apple will serve as an agent and take a 30 percent commission. Ebook editions of most newly released adult general fiction and nonfiction are expected to cost US$12.99 to $14.99.

Amazon has agreed in principle that the major publishers would be able to set prices in its Kindle store as well. But it’s also demanding that they lock into three-year contracts and guarantee that no other competitor will get lower prices or better terms, says the “Times.”

The iPad will come with an iBookstore app. will feature books from major and independent publishers. The free iBooks app lets you buy books from the iBookstore. Once you’ve bought a book, it’s displayed on your Bookshelf. Just tap it to start reading.