CBS Corp. plans to spin off this month its money-dragging radio business, whose holdings include such iconic stations as the all-news outlet 1010 WINS-AM in New York.

The company US:CBS, which began in 1927 as a radio company and is now part of media mogul Sumner Redstone’s empire, filed preliminary documents for an initial public offering with the Securities and Exchange Commission. The separation, which Chairman and Chief Executive Leslie Moonves disclosed in March at the company’s investor day, would follow a similar path as the 2014 spinoff of its outdoor-advertising unit.