Attorney General Andrew Cuomo is trying to figure out if banks provided the agencies with false information in order to get better ratings on the risky securities, said the person, who spoke on condition of anonymity because the investigation has not been made public.
Cuomo's office is investigating Goldman Sachs, Morgan Stanley, UBS, Citigroup, Credit Suisse, Deutsche Bank, Credit Agricole and Merrill Lynch, which is now part of Bank of America.
During the housing boom, Wall Street banks often packaged pools of risky subprime mortgages together. The securities were then typically given top-notch ratings and investors purchased them, in part, because of their high ratings.
The ratings, given out by Standard & Poor's, Moody's Investors Service and Fitch Ratings, are used as a guide for investors to judge how risky an investment might be.
As the housing market collapsed and more customers fell behind on repaying their mortgages, the securities began to fail.
The securities have been widely blamed for exacerbating the credit crisis and costing investors and the banks themselves billions of dollars in losses. The ratings agencies have come under fire for having given such high ratings to securities that were not safe.
