Google Inc. (GOOG) on Monday confirmed that it plans to launch a program that will let publishers sell digital versions of their books directly to consumers, a step that would thrust the Internet search giant into competition with e-commerce leader Amazon.com Inc. (AMZN).

Google, Mountain View, Calif., said it aims to build a "digital book ecosystem" to allow partner publishers to sell access to their titles, even if buyers don't have dedicated book readers such as Amazon's Kindle or Sony Corp.'s (SNE) Reader. The service was expected to launch by the end of this year.

News of Google's plans was first reported by the New York Times and later confirmed by the company.

Google could prove to be a significant challenger for Amazon, which sells e-books specifically formatted to work with its proprietary Kindle. A key difference would be that the search giant aims to let Google Book Search users "buy access" to copyrighted books with any Web-enabled computer, e-reader or mobile phone.

Google spokesman Gabriel Stricker said consumers would not be able to download books in the same way Amazon's customers can buy copies of specific titles and store them on their Kindle. Instead, people who access books through Google would be able to read titles online and temporarily cache them in their Internet browsers so they could also read them offline.

A consumer buying access to a book through Google Book Search would have the right to view the title in perpetuity, a source familiar with the matter said. It was not immediately clear whether consumers would be willing to pay for a book they could not download and store on their computer, phone or e-reader.

But a key advantage for Google is vast reach on the Internet. That's because the world's dominant search company could in theory highlight relevant books for sale every time a consumer punches in a search query.

Google said it would allow publishers to set their own prices, although the company reserved the right to discount titles at its own expense. Amazon typically charges consumers $9.99 per e-book, far below hardcover prices reaching about $26.

Google said it was still in talks with publishers and specific details of is project remain to be determined.

Susquehanna Financial Group analyst Marianne Wolk said Google could emerge as the world's largest e-book distributor, but its size and reach by no means guarantees the company will successfully challenge Amazon.

She said a key issue will be whether the e-book market evolves like the digital music market, in which Apple Inc.'s (AAPL) iPod was designed to play music available through its iTunes online store, or the PC market, in which multiple devices competed using the same open formats.

Google's push into book retailing should also help improve relations with publishers and authors, some of whom argued that the company's Book Search project to digitize more than 7 million books violated copyrights.

The company last year reached a legal settlement with authors and publishers, an agreement currently under antitrust review by the U.S. Department of Justice.

Separately, Amazon said Monday that it will launch its large-screen Kindle DX reader on June 10, earlier than initially expected.

-By Scott Morrison, Dow Jones Newswires; 415-765-6118; scott.morrison@dowjones.com