Mansfield's comments came in response to a question from BBC director general Greg Dyke, who asked how Capital would react if Clear Channel made a bid for Capital once the communications bill became law and permitted such a deal.
Speaking at the Radio Festival in Birmingham yesterday, Mansfield said: "There are some fundamental cultural differences in approaches between a company like Clear Channel and a company like Capital.
"Lowry Mays [Clear Channel chairman and CEO] said at this conference last year that his business was all about selling hamburgers and Fords. But we are driven by listeners."
The Capital Radio CEO added that the US group had said it would like to get involved in UK radio, but by invitation only. Mansfield confirmed that he "won't be picking up the phone".
Despite Mansfield's comments that Capital is led by its listeners, the radio group's flagship London station Capital 95.8 FM has been struggling with audiences.
In the last set of Rajars for the January to March period, Capital 95.8FM saw its weekly reach fall to 7.7m, down from 7.8m in the last quarter of 2002. Its share fell to 11.9% from 12.1% last time.
These disappointing audience figures have not put off interest from other companies however. In May, Jazz FM owner Guardian Media Group was reported to be considering a bid for Capital, following the communications bill and subsequent relaxation of media ownership rules.
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