New York—National radio ad revenue rose 3% in the first quarter compared with the same period in 2005, according to figures released Monday by the Radio Advertising Bureau. Local radio advertising dollars dropped 2%. The RAB report did not contain specific dollar figures. Total combined local and national ad sales fell 1%. It was a similar tune for radio ad sales in March: national ad dollars rose just 1% while local ad revenue fell 2%. The one bright spot: non-spot revenue grew 9% in the first quarter of this year compared with the year-earlier period.