U.S.-based media and entertainment company Liberty Media has proposed a plan to split off its Liberty Capital and Liberty Starz tracking stock groups. We are placing our 'BB-' corporate credit and senior unsecured debt ratings for the company on CreditWatch with developing implications. The CreditWatch listing reflects the possibility that the rating on the company's debt could be revised following our review of the capital structures of Liberty Media and the newly formed company. CHICAGO (Standard&Poor's) June 25, 2010--Standard&Poor's Ratings Services today placed its 'BB-' corporate credit rating, as well as the 'BB-' senior unsecured debt rating, for Englewood, Colo.-based Liberty Media Corp. on CreditWatch with developing implications, meaning the ratings could be raised, lowered, or