New York - Online retailer Amazon.com on Wednesday unveiled a new version of its Kindle electronic reading device that it said could help newspapers, magazines and textbooks make the transition to the digital age.

The new device features a much larger 9.7-inch (24.6-centimetre) screen than its two Kindle predecessors. This should make it more useful for reading formats that are larger than the standard paperbacks that have been Kindle's most popular content so far. The device is less than a centimetre thick and comes with 3.3 GB of memory, which Amazon says is enough to store up to 3,500 books.

Amazon teamed up on the Kindle DX with a number of US publishers, including the Washington Post, the New York Times and the Boston Globe, which will offer the 489-dollar Kindle at a discount in return for long-term subscriptions.

Five universities, including the Ivy League Princeton University, have also signed up to distribute hundreds of Kindles on which students will be able to take notes, highlight information and store all their textbooks. Textbook publishers that account for 60 per cent of the US market have signed on to offer their books through the Kindle.

"The Kindle DX holds enormous potential to influence the way students learn," said Barbara R Snyder, president of Case Western Reserve University. "We look forward to seeing how the device affects the participation of both students and faculty in the educational experience."