A Bertelsmann Heir Jockeys to Be Heir Apparent
Christoph Mohn, great-great-grandson of founder of Bertelsmann AG, is thought to be most likely to take place of aging patriarch Reinhard Mohn as leader of family and business; Reinhard Mohn's wife, Liz, was instrumental in prodding Bertelsmann's board to dismiss company's chairman Thomas Middelhoff two weeks ago, reportedly because she feared his drive to take Bertelsmann public would erode her family's control over company; Christoph Mohn, 37, has rotated through many parts of Bertelsmann empire; his apprenticeship has exposed him to rich mix of high-brow and mass-market entertainment put out by Bertelsmann; photos (M)
