NEW YORK--(BUSINESS WIRE)--Fitch Ratings has taken the following rating actions on tranches from eight collateralized debt obligations (CDOs) backed primarily by Trust Preferred (TruPS) securities issued by banks and insurance companies: --Affirmed 57 tranches; --Upgraded eight tranches. KEY RATING DRIVERS Credit Quality of Collateral: For all of the transactions, the credit quality of the collateral portfolios, as measured by a combination of Fitch's bank scores and ratings, remained stable or