Writer Edward Klein's unauthorized biography of Katie Couric includes charges that she deliberately undercut colleagues on the Today show -- restricting Ann Curry's interview assignments and deliberately prolonging her own interviews so that they would eat into Matt Lauer's airtime. Unveiling excerpts from the book, Katie: The Real Story, due to be published next Tuesday, the New York Daily News said that it contains the allegation that Lauer threatened to quit Today if NBC renewed Couric's $65-million contract. The book also says that since the precipitous decline in the ratings for the CBS Evening News, Couric's editorial control over the program has diminished. Meanwhile, Couric's predecessor, Dan Rather, said during an interview on Fox News Tuesday that Couric's job is safe so long as Les Moonves remains the head of CBS. "Katie Couric was his hire and you can bet that he will play defense as hard as he possibly can," Rather said.