Random House Inc. continues to add to its publishing portfolio through niche purchases. In a deal announced last week, Random's Ballantine Books division acquired the military book publisher Presidio Press.

Based in Novato, Calif., Presidio publishes about 25 titles annually in trade paperback and hardcover and has a backlist of about 150 titles. Ballantine will retain the Presidio name as an imprint. The company will stay at its present location, with Presidio president Richard Kane serving as publishing director, reporting to Ballantine president Gina Centrello. Kane said acquisition discussions were initiated by Ballantine as a way to expand its military book list, which had included about 200 titles. "The demand for titles about military affairs seldom wavers," Centrello explained, adding, "interest in the subject has greatly increased these past few months."

Presidio was founded in 1974 as a publisher of scholarly military books, but by the early 1980s it had evolved into a publisher primarily of trade books with a focus on narrative history titles about World War II and the Vietnam War. Presidio has done very well with a series of books by Keith Nolan that began in the early 1980s with The Battle for Hue up through his most recent book, The Battle for Saigon. Other titles that have done well include With the Old Breed at Peleliu and Okinawa and Common Sense Training.

The company also publishes a limited number of novels and was the original publisher of Defcon One by Joe Weber. After publishing several books with Putnam, Weber has returned to Presidio, which has just released Dancing with the Dragon in a 25,000-copy first printing.