All the books were published before 1923 and include such classics as Charles Dickens' A Tale of Two Cities, Jane Austen's Sense and Sensibility, Mark Twain's A Connecticut Yankee in King Arthur's Court, and Herodotus' The Histories. The books can be browsed by subject, author or title, and the full text can be searched.

600,000 Titles

The books have been available as PDF downloads, which works well for computer screens but not e-book readers. Google will provide the public-domain works to Sony in EPUB, or electronic publication format, which flows the lines to fit on a small screen. Amazon's Kindle e-book device uses its own file format, but EPUB is common among publishers.

Sony said the deal vaults its Reader past the Kindle, since the Reader will now have the larger e-book library with about 600,000 titles. The Kindle has more than 245,000 titles, and allows users to download wirelessly. For Sony's Reader, a user first has to download the titles to a computer, and then from the computer to the Reader.

A user could also read the public-domain books for free on a computer, after downloading Sony's free eBook Library Software and registering an account.

A Google spokesperson told news media that it wants to make the books available as widely as possible, on any device.

'Icing on the Cake'

Michael Gartenberg, a vice president at Interpret, said the e-book wars are "definitely" heating up, but added that he doesn't think the Google titles will help Sony much.

"With due respects to the classics" and other books among the Google titles, Gartenberg said, adding titles "that most people don't want to read isn't going to help Sony in its battle with the Kindle."

Some people may want to read some of the titles, he said, but most people "want to read current books and best-sellers." These kinds of public-domain titles, he said, "should be the icing on the cake once you have a good e-book library in place." Sony needs to be adding more recent titles to its library, he said, as well as doing more deals with publishers and revising its pricing structure.

Ross Rubin, director of industry analysis for consumer technology at the NPD Group, agreed that public-domain content isn't as much of a draw as, say, New York Times best-sellers. But, he added, "both e-book devices still appeal only to a relatively small group -- high-volume readers."

What's needed for e-book devices, he said, is to move from the "nice-to-have" category to "must-have" by acquiring a high-value content source such as textbooks.