NEW YORK (Standard&Poor's CreditWire) Aug. 31, 1999--Standard&Poor's today assigned its preliminary triple-'C'-minus rating to CD Radio Inc.'s $500 million Rule 415 shelf registration. The outstanding triple-'C'-plus corporate credit and senior secured debt ratings for the company were affirmed. The rating outlook remains negative. The preliminary triple-'C'-minus rating is the rating that would likely be assigned if the company issues senior unsecured or subordinated debt under the shelf registration. The senior unsecured debt rating is notched down two notches from the corporate credit rating due to the significant layer of secured debt in the company's capital structure. Preferred stock issued under the shelf would be rated based on features of the particular issue. Ratings reflect the substantial