NEW YORK (Standard&Poor's) Jan. 16, 2009--Standard&Poor's Ratings Services said today it lowered its corporate credit rating on Sirius XM Radio Inc. to 'CCC' from 'CCC+'. We also lowered the issue-level ratings on the debt of Sirius XM Radio Inc. and of Sirius' unrestricted subsidiaries, XM Satellite Radio Holdings Inc. and XM Satellite Radio Inc., which remain on CreditWatch, though the implications are revised to negative from developing. We could affirm or lower the issue-level ratings pending our review of additional information and follow-up discussions with management. The outlook is negative. New York City-based Sirius XM had total debt outstanding of $3.37 billion as of Sept. 30, 2008. "The downgrade reflects our increased concern over the company's