Moody's Investors Service downgraded Harrah's Entertainment to Ca and $16 billion worth of its debt from B3 to Caa1. The lowered ratings reflect a substantial risk of default by Harrah's and follow its announcement of a $2.1 billion debt exchange program. The company is attempting to refinance some of the debt resulting from its $17 billion LBO by TPG Capital, The Blackstone Group, and Apollo Investment Management in January.