The losses keep piling up. Leading brokerage firms are likely to write down the value of $200 billion of loans they have made to corporate clients by $10 billion to $14 billion during the first quarter of this year, Meredith Whitney, an analyst at Oppenheimer, wrote in a research report last week.

Those institutions and global banks could suffer an additional $20 billion in losses this year on commercial mortgage-backed securities and other debt instruments tied to commercial mortgages, according to Goldman Sachs, which predicts commercial property prices will decline by as much as 26 percent.

Analysts at UBS go further, predicting the world’s largest banks could ultimately take $123 billion to $203 billion of additional write-downs on subprime-related securities, structured investment vehicles, leveraged loans and commercial mortgage lending. The higher estimate assumes that the troubled bond insurance companies fail, a possibility that, for now, is relatively remote.

Such dire predictions underscore how the turmoil in the credit markets is hurting Wall Street even as the Federal Reserve reduces interest rates. Already, once-proud institutions like Merrill Lynch, Citigroup and UBS have gone hat in hand to Middle Eastern and Asian investors to raise capital. “You don’t have a recovery until you have the financial system stabilized,” Ms. Whitney said. “As the banks are trying to recover they will not lend. They are all about self-preservation at this time.”

One of the latest areas to come under pressure is the leveraged loan market. In recent weeks the market for these corporate loans plummeted, driven by fear that banks have too many loans to manage. Prices have fallen as low as 88 cents on the dollar, levels not seen since 2002, when default rates were more than 8 percent. Loans to some companies, like Univision Communications and Claire’s Stores, are trading in the high 70s, analysts say.