Further, from the WSJ (subcription required):
After MF Global moved the money, J.P. Morgan's chief risk officer, Barry Zubrow, called Mr. Corzine to seek assurances that the funds belonged to MF Global and not to customers, according to the subcommittee's memo.
J.P. Morgan then sent Mr. Corzine a drafted letter to be signed by Ms. O'Brien and give "broad assurances" that all transfers "past, present and future" complied with federal regulations stipulating that customer funds mustn't be commingled with a financial firm's own money.
Laurie Ferber, MF Global's general counsel at the time, reviewed the letter but thought it too broad and sought to restrict its scope to only the Oct. 28 transfer, according to the congressional memo. Other emails revealed that, after further drafts of the letter circulated, Ms. O'Brien was reluctant to sign it, the memo said.
A J.P. Morgan spokeswoman declined to comment.