Google Inc. on Tuesday said it is working with major university libraries to scan their collections and make them searchable online, a huge undertaking that reflects how the search giant is inching into markets that could someday put it into direct competition with giant Internet retailer Amazon.com.

The project involves digitally scanning the library collections of Harvard, Stanford, the University of Michigan, the University of Oxford and The New York Public Library, the Mountain View, Calif., search giant said. The effort is an expansion of the Google Print program, a service that assists publishers in making books and other offline information searchable online.

Google won't disclose how many books are currently searchable in the program, but said the University of Michigan, for example, has more than 7 million books in its collection. Harvard has more than twice as many books.

"It will take years to do, and our goal is to do it quickly, but there's a lot of challenges along the way and we'll have a better estimate (of the time it will take) as we get further along," Susan Wojcicki, director of product management for Google, said.

A large portion of Google's revenues are generated through paid search results, so increasing the comprehensiveness of its search engine is the strategy for driving more traffic to the site, Wojcicki said. For now, there will be no separate interface for book searches.

The latest project offers more insight into Google's business strategy, compared with those of rivals Microsoft Corp. and Yahoo Inc., Allen Weiner, analyst for market researcher Gartner Inc., said. The Google competitors offer search as part of their news, entertainment and shopping web portals.

"It looks like Google is going to use its search as the trigger for its economic foundation," Weiner said.

Google Print moves the company into competition with Amazon.com and other booksellers.

"I see them competing head on with Amazon here," Weiner said. "Where it's been Google against Yahoo and Microsoft, it's now Amazon too."

In marketing Google Print, the company says the program can generate book sales for publishers and authors via "Buy this Book" links and advertising. The offering enables people to browse the full text of public domain works, and brief excerpts and bibliographic data of copyrighted material.

Other companies, such as Ebrary Inc., scan book collections for libraries, making them available over the Internet. The size of Google's undertaking, however, makes it particularly interesting for search experts, who wonder whether people will actually be able to find what they want.

"Just including content doesn't mean people will be able to find it," Gary Price with SearchEngineWatch.com said. "I'm interested in seeing where they'll be in a year or two, and what type of access (to books) the typical searcher will have typing just two or three words."