Sony Corp is making available public domain books from Google Inc to users of its electronic book reader, Sony said on Wednesday, vastly increasing the amount of available content on the device.

That will boost the available titles in Sony's eBook Store to more than 600,000, Sony said.

Sony sells two versions of its Reader, which competes directly with Amazon's Kindle. Kindle users can access over 245,000 titles plus newspapers, magazines and blogs.

Whereas Amazon touts its relationship with publishers and access to a wide range of best-selling titles -- which generally cost $9.99 -- as a selling-point for the Kindle, Google has sought to make its collection of public domain books widely available.

Public domain books, whether Jane Austin's Persuasion or Leo Tolstoy's War and Peace, are no longer protected by copyright.

Last month, Google announced it was making the collection easily accessible to mobile devices such as the iPhone, and Amazon has said a similar move was afoot at the company.

Sony Reader users will be able to read the Google books on their devices, or download a PDF file to read on a computer. The books are already accessible over the Internet at http://www.books.google.com.

(Reporting by Alexandria Sage; editing by Carol Bishopric)