The Securities and Exchange Commission plans to urge financial services companies, including banks and insurance firms, to disclosure more information about their exposure to potentially problematic loans in light of the massive number of gargantuan write-offs caused by the sub-prime lending crisis.

SEC chairman Christopher Cox told reporters Monday that the regulator was planning to send letters to the CFOs at about two dozen firms, including Wall Street investment banks, the Associated Press reported.

The letters were to be sent to companies that have already disclosed off-balance-sheet investments in collateralized debt obligations, conduits, and structured investment vehicles, according to the report.

The letters state that investors would be interested in ratings on off-balance-sheet investments, including downgrades or write-downs, any difficulty in funding such investments, and the maximum losses to be borne by first loss note holders, the AP wrote.

The SEC also wants companies to disclose any obligations to these kinds of investments, such as purchasing assets or providing liquidity, and how they stack up against other liquidity providers, according to the AP.

In addition, the letters reportedly call on companies to outline known trends or uncertainties that could have a big effect on the company’s operations, liquidity, or capital resources.

Cox said the management disclosure and analysis (MD&A) portion of annual reports would be “a wonderful place” for top corporate executives to discuss sub-prime exposure and alert investors to possible problems, according to Dow Jones.