German media conglomerate Bertelsmann AG is buying Random House, the largest U.S. book publisher, in a deal that brings some of the world's most famous authors under one roof.

The purchase price was not disclosed in Monday's announcement by Bertelsmann. The combined publishing business will retain the Random House name.Bertelsmann owns Bantam Doubleday Dell, publisher of John Grisham, and has been looking to expand its English-language consumer publishing business.

Random House, owned by Advance Publications Inc., has published best-selling authors Michael Crichton, Norman Mailer and John Updike. Advance decided to sell the publisher to focus on its main businesses of newspapers, magazines, business journals and cable TV.

The privately held Advance, owned by the Newhouse family, includes The New Yorker, GQ and Vanity Fair among its publications.

Bertelsmann, the world's third-largest media and entertainment company behind Time Warner Inc. and Walt Disney Co., adds another well-known name to its stable of properties through the purchase. The company owns the BMG music club, the RCA and Arista record labels, and McCall's and Family Circle magazines, among others.

Random House will also provide a wealth of titles for a new online book-selling venture that Bertelsmann is planning to compete with and Barnes & Noble. Bertelsmann announced plans last month to develop Books-On-line, which aims to sell titles by all publishers in several languages.

"Our new company will draw and build upon the strengths of two great publishing traditions . . . with an unprecedented diversity of publishing choices," said Peter Olson, current chairman of Bertelsmann Book Group North America, who will head the new Random House.

The company combines a variety of publishing imprints: Doubleday, Bantam Books, Dell-Delacorte and Broadway Books from Bertelsmann and Random House, Knopf, Crown and Ballantine from Advance.

Random House was founded in 1927 by Bennett Cerf and Donald S. Klopfer.