It's been six weeks since the MF Global collapse and its former chief Jon Corzine, who was been absent from public view since the firm's collapse in late October, is expected to appear before a congressional hearing tomorrow according to a witness list released by the committee.  Congress is holding hearings to examine the firm's bankruptcy and the search for up to $1.2 billion in missing customer money.  This would be the first hearing to feature Corzine, whom the committee subpoenaed to testify.  It is unclear if Corzine will invoke his right to avoid self-incrimination under the Fifth Amendment of the U.S. Constitution.  Also due to appear at Thursday's hearing along with Corzine are, Jill Sommers, who is heading up the CFTC's review of MF Global, James Kobak, the lead counsel for the trustee liquidating MF Global; Terrence Duffy, executive chairman of the CME Group; William J. Brodsky, chairman and CEO of the Chicago Board Options Exchange; Dan Roth, president and CEO of the National Futures Association; and Stephen Luparello, vice chairman with FINRA.  Regulators have been criticized for neither closely policing the firm nor catching the potential misuse of customer money. A Senate Agriculture Committee has also voted to subpoena Corzine to testify before its December 13 hearing.   [Reuters 12/6/11]