Sony Corp has announced the availability of over 1 million public domain books on its electronic readers via Google Inc`s Books project, which digitizes classic titles not protected by copyright. Titles purchased through Sony's store are accessible only on the company's reader. Sony was the first to market with its Sony Reader in 2006 and now sells two versions of the device.

Besides, Sony, Amazon.com, Barnes & Noble Inc and others are racing to beef up their offerings to meet growing demand for digital books on electronic readers: tablet-like devices where whole books can be stored and read. The companies are trying to establish a toehold in a market they believe will eventually become a profit driver, although the devices do not appeal to all readers, due to their cost and technical issues yet to be fully resolved.

Furthermore, U.S. bookseller Barnes & Noble declared last week the world's largest online bookstore, with more than half a million public domain books from Google. Amazon's Kindle store offers over 300,000 titles. The Seattle-based online retailer declined to comment on whether it planned to add Google's titles as well. In addition, privately owned Plastic Logic plans to enter the market early next year with its own e-reader, and Barnes & Noble said it will be that device's exclusive provider of digital books.

The closed system of sharing is one of major issues impeding consumer adoption of digital readers. Thus, titles purchased from the Kindle Store can be read on the Kindle and Apple Inc's iPhone or iPod Touch, but not on the Sony Reader. Meanwhile, Barnes & Noble's titles are accessible on Apple devices and Research in Motion Ltd's Blackberry, but not on the Kindle or Sony Reader.