Complex sentence: Rantzen was one of the founders of TV-am, the company selected to launch ITV's breakfast television service, but before the station went on air in 1983, Rantzen dropped out, opting to remain with the BBC.
Split into simpler sentences: Rantzen was one of the founders of TV-am, the company selected to launch ITV's breakfast television service. But before the station went on air in 1983, Rantzen dropped out, opting to remain with the BBC.