Celebrity Redstone's Blockbuster Divorce By People Staff Published on December 30, 1998 12:00 AM Share Tweet Pin Email The wife of media mogul Sumner Redstone has stepped down as a member of the board of directors of National Amusement Inc., the parent company of media conglomerate Viacom Inc. (which owns Paramount, CBS, Blockbuster Video, MTV and other properties). Phyllis Redstone, 74, earlier this month filed for divorce from her husband of 52 years (amid reports of his alleged sexual affair with a young film executive). Redstone is chairman and CEO of Viacom. Mrs. Redstone resigned “to avoid any suggestion that their personal difficulties might interfere with the operation of the family’s business endeavors,” attorneys for both sides said. Sumner Redstone, 76, has a fortune estimated by Forbes magazine to be worth $9.4 billion.