Bestselling author Dean Koontz has inked a deal to publish his next three full-length fiction titles with Bantam Books, a division of Bantam Doubleday Dell Publishing Group, whose corporate parent is Bertelsmann AG.By signing with Bantam, Koontz leaves Knopf, a subsidiary of Random House, for whom he has written his last three novels. In February, Knopf will publish “Sole Survivor,” the final title in his current hardcover/softcover pub deal with the imprint. Knopf published “Dark Rivers of the Heart,” in 1994 and “Intensity” earlier this year. Bantam acquired North American hardcover/softcover publishing and book club rights to the novels. Koontz is currently at work on the untitled first novel, which Bantam has scheduled for hardcover publication in 1998. The terms of the deal were not disclosed, but a source said it was a multimillion-dollar package, commensurate with Koontz’s stature in the book world. “What is most exciting for Bantam is that we welcome Dean Koontz to our list as an established No. 1 bestselling author,” said Irwyn Applebaum, Bantam’s president and publisher. Applebaum announced the deal Monday at the annual BDD sales meeting in Key Biscayne, Fla. “We believe his storytelling powers keep growing stronger and stronger, and we are looking forward to bringing an even wider readership to these forthcoming books.” Select group With seven No. 1 New York Times hardcover bestsellers, eleven No. 1 bestselling paperbacks and book sales totaling more than 175 million copies worldwide, Koontz is one of a handful of proven star authors coveted by publishers. The deal represents a coup for Bantam, for which Koontz will become the imprint’s biggest fiction name. He will join bestselling Doubleday authors John Grisham, Margaret Atwood and Danielle Steel in the BDD fold. “I am delighted to be joining forces with Bantam,” Koontz said, “where the vision of publishing’s future is so similar to mine, and where creativity is apparent in every department. I expect to have a long and exciting career with Bantam. “I have not embarked on this change for financial reasons. I have been proud to be published by Knopf and Ballantine, and I value the time that I spent with everyone there, and the work they did on behalf of my books.” Before joining Knopf in 1993, Koontz’s longest association with a publisher was with Putnam, which published 13 of his works, beginning in 1977. Film frustrations While several of his books have been optioned for film, Koontz was reportedly frustrated with the sluggish development process in feature films, and has turned toward TV miniseries as an outlet for his work. Mandalay Entertainment optioned the rights to both “Intensity” and “Sole Survivor” for Fox TV Network miniseries. The “Intensity” mini is slotted to air on Fox in May. A feature adaptation starring Peter O’Toole of “Phantoms,” a novel published by Putnam in 1983, will be released by Miramax next year. Koontz was repped in the Bantam deal by William Morris’ Robert Gottlieb.