United States Cellular Corp and BellSouth Corp are to exchange cellular clusters. US Cellular will receive a controlling interest in a 12-market cluster that provides cellular service to most of Wisconsin, including the Milwaukee market, and parts of northern Illinois. BellSouth will receive a ninemarket cluster in southern Indiana and Kentucky, a controlling interest in one market in central Tennessee, investment interest in 13 other markets and an undisclosed amount of cash, US Cellular said.