Clear Channel Communications, the nation’s largest radio operator, is now considering selling some of its 1,200 stations in smaller markets after years of acquiring everything in sight, according to industry analysts. The Corporation">CBS Corporation did the same thing recently and now says it is looking at further station sales. The Walt Disney Company struck a deal this summer to get out of the radio business altogether, and in May, Susquehanna Broadcasting, the nation’s largest privately held radio group, was sold to another broadcaster.