The PRS-700 features a similar 6-inch electronic paper display to that used in the PRS-505 that's currently on sale but added to the screen in the new model is a touch panel and a reading light. The touch panel means users will be able to turn pages on-screen and also search through e-books by using an on-screen keyboard and highlight passages using a stylus. The light will aid reading in dark environments.

Like the current model, the PRS-700 can store about 350 e-books in its internal memory and more can be kept in Memory Stick or SD Card media. Sony says the battery supports up to 7,500 pages of continuous reading. It's compatible with e-book formats including Sony's BBeB (Broadband electronic book), Microsoft Word documents, Adobe PDF and the International Digital Publishing Forum's XML-based EPUB format.

Sony hasn't offered detailed specifications of the device but says it's about the size of a "slimmed-down paperback book" and weighs "about 10 ounces" (280 grams). The PRS-505 weighs 260 grams.

It will be available from next month and will cost US$400, which is $100 more than the PRS-505 model that will remain on sale. Launch plans for areas outside of the U.S. were not disclosed.

The launch comes as Sony kicks off a month-long campaign to promote e-books that coincides with National Book Month. The company is deploying e-book sales teams across the U.S. to promote the devices and at an event in New York has Dave Farrow, a speed-reader and memory expert, living in a storefront for a month reading books on the device. For each page Farrow reads, Sony is donating a library of 100 electronic books to a school. The first 100 schools that begin downloading their e-books will also get five e-book readers, Sony said.