Seeking the next big family-film franchise, Illumination Entertainment and Universal Pictures have acquired the rights to Jonathan Stroud’s supernatural book series “Lockwood & Co.” with plans to turn the first book, “Lockwood & Co.: The Screaming Staircase,” into a live-action pic.Illumination Entertainment CEO Chris Meledandri will produce. Stroud is a prolific children’s and young-adult fantasy author whose “Bartimaeus” trilogy has sold 6 million copies worldwide. The first book is set to be released next autumn. The London-set series follows Lockwood & Co., a ramshackle psychic detection agency that contends with murderous specters and terrifying apparitions. Lockwood and his colleagues must seek a solution to an epidemic of ghosts known as “the Problem.” Illumination Entertainment VP of development Kit Giordano championed the acquisition of the highly sought after “Lockwood & Co.: The Screaming Staircase” and will oversee development for the company. The series was one of the most talked-about properties at the recent London Book Fair even though no one had yet read the first book. Studios continue to pursue projects with similarities to “Harry Potter” in hopes of creating another fantasy franchise. Though bidding was not quite at the level of that for “Fifty Shades of Grey,” Stroud and his team were at one point in exclusive negotiations with another studio. Once the exclusivity on the negotiations had expired with the other studio, a proposal along with the first six chapters was sent out to several studios, which all put out preemptive offers on the material. Most of the bidders were prepared to fly to London, where Stroud lives, to meet with the author and discuss where he saw the story going. Though Illumination’s background is in animation, sources said the producer of “The Lorax” and “Despicable Me” was chosen by the publisher because the shingle was fully committed to put all its resources behind its first live-action pic. Sources close to Illumination said additional live-action films can be expected from the company. Random House Children’s Books will publish the book in the U.K., while Disney-Hyperion will handle the publishing in the U.S. The Lockwood storyline will ultimately comprise multiple books. Illumination is currently in post on “Despicable Me 2,” which bows on July 3, and is going into production on the untitled “Minions” spinoff for release in 2014. “The Lorax” has grossed more than $345 million at the worldwide B.O. The Stroud series film rights are represented by Emily Hayward at Knight Hall Agency Ltd. on behalf of Laura Cecil.