Standard & Poor’s Ratings Services downgraded its ratings Thursday on $2.3 billion in collateralized debt obligations (CDOs) that rely in part on subprime mortgages for collateral.
The new ratings on 50 tranches from 12 CDOs stem from earlier downgrades by Standard & Poor’s of more than 1,000 classes of mortgage-backed securities (MBS) held by some of the downgraded CDOs.
On July 12, 2007, Standard & Poor’s lowered its ratings on more than 600 classes of MBS classes collateralized by first-lien subprime mortgages. A week later, the ratings agency dowgraded more than 400 MBS classes backed by subprime loans.
Most recently, Standard & Poor’s on Aug. 7 said it was reviewing more than 200 MBS classes backed by Alt-A mortgage loans for possible downgrades.
Thursday’s downgrades bring the total number of downgraded CDO tranches to 75, with an estimated value of $3.29 billion.
Another 127 tranche ratings from 41 cash flow and hybrid CDO transactions are currently on CreditWatch negative for possible downgrade.
Standard & Poor’s said it affirmed its previous ratings on another 19 tranches from six CDOs, removing them from CreditWatch negative.