Standard & Poor's downgraded $43.74 billion European CDOs after updating ratings criteria in September.
S&P said it downgraded 525 ratings on 395 CDOs. Another 354 were affirmed, 89% of which were already in highly speculative territory.
The rating agency put 1,626 European CDO ratings on watch for downgrade in September after releasing the new global criteria, which at that time, S&P said would make the ratings more comparable to those in other sectors.
The latest announcement dealt with the last of the European synthetic CDOs under review. Cash flow and hybrid corporate CDO deals remain under review, and S&P said it expects to complete the review by April.