“The Witching Hour,” a trilogy of novels Anne Rice wrote in the early 1990s as a respite from her vampire chronicles, has found new life in print and will be adapted as a limited TV series that producer Mark Wolper is developing at Warner Bros.The novels, “The Witching Hour,” “Lasher” and “Taltos,” introduced the Mayfair witches, members of a prominent and wealthy New Orleans family whose saga has woven its way into Rice’s ongoing vampire chronicles. Rice, repped by CAA, publishes a new novel once every two years or so. Her next novel, “Blackwood Farm,” which comes out next fall, will feature both vampires and Mayfair witches. The last book to unite the two series was “Merrick,” published in 2000. Both series involve long, intricate family histories of the sort that may well be better explicated in a limited series than in a feature film. “Queen of the Damned,” which has eked out $30 million to date, focuses on the vampire Lestat, and his relation to the 6,000-year old bloodsucker, Akasha. “Witching Hour” will be exec produced by Wolper and Rice. AFTER A DOWNBEAT 2001, marked by political anxiety, slumping sales and downsizing, the book biz is showing signs of life. John Grisham and a raft of “Lord of the Rings” tie-ins drove January sales to dramatic heights, with hardcover sales up 93.6% over last year, and adult paperback sales up 48.4%. Amy Gwiazdowski, a spokesperson for the Association of American Publishers, says its too soon to say whether these figures augur well for a healthy 2002. Returns of books sold in January — which can wreak havoc on a publisher’s bottom line — won’t be measured for months, and Feb. and March sales statistics aren’t yet available. But returns also appear to be falling. In January, returns of adult hardcover books were down more than 20%, and returns of kids hardcovers were down 30%. “LORD OF THE RINGS” may be an AOL TW franchise, but the book sales benefit the burgeoning publishing empire of Vivendi U. VU bought Tolkien’s publisher, Houghton Mifflin, last year, and promised shareholders tens of millions in synergistic cost-savings once the company was integrated with its other assets. Agnes Tourraine, Paris-based chief of Vivendi U Publishing, said this week Vivendi had already achieved $40 million in savings involving paper and printing costs. Tourraine also said the publishing company is moving aggressively into the console-based vidgame business. Universal Interactive is developing games based on “The Mummy Returns” and “Shrek.” But Vivendi U has yet to make the most of its film and lit synergies: The “Mummy Returns” novelization is published by an imprint of Penguin Putnam. And “Shrek,” the kids book by William Steig, is published by Farrar, Straus & Giroux. ANOTHER REASON FOR OPTIMISM is that Americans who steered clear of the Frankfurt Book Fair descended on London in droves last week for the London Book Fair, which opened Sunday. Attendance Sunday was up 5.6%, and, most significant for those dealing in lit rights, the hall space reserved for agents and scouts is choked with traffic. This year, the fair has crammed 110 tables into the International Rights Center — a hangar-like balcony in the Olympia Exhibition Center in Kensington. Last year, there were 88 tables. That’s a trend worth watching in Hollywood. The Rights Center is where buyers and sellers gather to pick over lists of forthcoming books from around the world. And there’s a wealth of Hollywood execs attending this year, including staffers from Universal, Scott Rudin Prods., APG, Tribeca Films and New Line.