Officials from the three credit-rating agencies could not be reached for comment. A lawyer in Batson's office also could not be reached. For nearly a year, Batson has been gathering mountains of documentary evidence from hundreds of Wall Street banks and law firms that did work for Enron. Back in August, for instance, similar document requests were served on Citigroup ( C ), J.P. Morgan Chase ( JPM ), Merrill Lynch ( MER ) and Credit Suisse First Boston, a division of Credit Suisse Group ( CSR ). This is the first time he's sought information from the credit-rating agencies that had blessed Enron's corporate debt with an investment grade rating. Batson has been charged by the bankruptcy court with trying to unravel the dozens of off balance sheet entities Enron used to hide billions of dollars in debt and artificially inflate its earnings.