NEW YORK (Standard&Poor's CreditWire) Jan. 25, 2000--Standard&Poor's today assigned its triple-'B'-minus rating to Liberty Media Corp.'s $1 billion Rule 144A offering of senior debentures due 2030. At the same time, Standard&Poor's affirmed its triple-'B'-minus corporate credit rating for Liberty Media. The triple-'B'-minus rating on the company's $2 billion of public senior unsecured debt also was affirmed. Ratings reflect Liberty Media's considerable portfolio of media and related investments (both wholly and partially owned), the support that operating cash flow could offer for debt service, and the value conferred by management's long experience in the industry. These strengths are tempered by concerns that liquidity support for debt service is diminishing as cash is deployed in acquisitions,