Microsoft said on Thursday it would offer improved capacity to search copyrighted books on the Internet as the company battles Google for advertising dollars from Web-based services.

Microsoft said it had received permission from dozens of publishers including Cambridge University Press, McGraw-Hill Cos Inc. and Simon & Schuster, a CBS Corp. unit, to use their copyrighted titles.

The changes to its Live Search Books comes months after Microsoft attacked Google for what it called the Web search leader's approach to copyright protection in services like Google Book Search.

The world's top software maker said Google's ambitious plan to scan millions of published works and make them available via its search system without first gaining copyright holders' permission could open the door to massive infringement.

Microsoft's Live Search Books is part of its "Live" online services aimed at augmenting its dominance in desktop software with a host of Web offerings to rival Google. Both companies aim to make money from Web services through advertising.

Microsoft said Live Search Books would now include a counter telling how many pages are left within the number of pages they are allowed to view, and tools to allow people to more easily search within books using specific keywords.

The preview pane will include a cover image, book summary and table of contents and the system will have links allowing readers to buy books from online retailers or the publisher.