Last month, the Boston Library Consortium of 19 research and academic libraries in New England that includes the University of Connecticut and the University of Massachusetts, said it would work with the Open Content Alliance to begin digitizing the books among the libraries’ 34 million volumes whose copyright had expired.

“We understand the commercial value of what Google is doing, but we want to be able to distribute materials in a way where everyone benefits from it,” said Bernard A. Margolis, president of the Boston Public Library, which has in its collection roughly 3,700 volumes from the personal library of John Adams.

Mr. Margolis said his library had spoken with both Google and Microsoft, and had not shut the door entirely on the idea of working with them. And several libraries are working with both Google and the Open Content Alliance.

Adam Smith, project management director of Google Book Search, noted that the company’s deals with libraries were not exclusive. “We’re excited that the O.C.A. has signed more libraries, and we hope they sign many more,” Mr. Smith said.

“The powerful motivation is that we’re bringing more offline information online,” he said. “As a commercial company, we have the resources to do this, and we’re doing it in a way that benefits users, publishers, authors and libraries. And it benefits us because we provide an improved user experience, which then means users will come back to Google.”

The Library of Congress has a pilot program with Google to digitize some books. But in January, it announced a project with a more inclusive approach. With $2 million from the Alfred P. Sloan Foundation, the library’s first mass digitization effort will make 136,000 books accessible to any search engine through the Open Content Alliance. The library declined to comment on its future digitization plans.

Image Bernard Margolis, president of The Boston Public Library. Credit... Robert Spencer for The New York Times

The Open Content Alliance is the brainchild of Brewster Kahle, the founder and director of the Internet Archive, which was created in 1996 with the aim of preserving copies of Web sites and other material. The group includes more than 80 libraries and research institutions, including the Smithsonian Institution.