Jane Friedman's departure as HarperCollins CEO, first reported by Gawker, has been officially confirmed by the book publisher. Her replacement by Brian Murray, 21 years her junior, comes less than a month after a similar generational shift at Bertelsmann AG's Random House, where unsentimental German engineer Markus Dohle, 39, replaced book-loving lawyer Peter Olson, 58. The young book executives hope to fix slowing growth and to better exploit the explosion in online digital media. But it's not clear whether broad technology trends had much to do with the departure of Friedman, who got her start as a Knopf dictaphone typist four decades ago, went on to become a pioneer in audio books and online marketing and who led a unique and ambitious push to digitize HaperCollins' collection. As a surprised fellow executives groped for answers about the change last night, some speculated it might even have its roots in late 2006, when Friedman, with the backing of Roger Ailes, squelched the a high-profile book overseen by HarperCollins executive Judith Regan by alleged killer OJ Simpson, then pushed Regan out of the company in the wake of Regan's remarks about Jews. As one former News Corp. insider put it: