The head of the U.N. arms inspection team in Iraq, who found himself in the center of a firestorm as the U.S. prepared to attack without the sanction of the world body, has written a book that Pantheon plans to publish here next spring. Dan Frank bought the untitled book, in which Hans Blix describes his struggles to gain more time as war approached, from Jane Gelfman at Gelfman & Schneider, co-agenting for Curtis Brown in London. The book will be widely published elsewhere, with the London agency having sold British rights to Bloomsbury, and translations in France, Germany, Italy, Spain and Holland; Bonnier in Sweden has Scandinavian rights, which it is selling on.