Columbia TriStar Home Video president Pat Campbell has left the company, joining Ameritech, a Chicago-based communications and information services supplier, as its executive VP of corporate strategy and business development.The move confirmed industry speculation that Campbell would depart the Sony vid arm, which has been awash in a sea of red ink for the past several years. Campbell’s move also signals an impending reorg of CTHV, which sources said is expected to be announced this week. It also follows the recent departure of Bill Perrault, the vidarm’s VP of marketing, who took a post at interactive software publisher Compton’s New Media. Campbell joined RCA/Columbia Pictures Intl. Video, the first incarnation of CTHV, as its president in 1984.