Former New Jersey Governor and Princeton U. visiting lecturer Jon Corzine resigned from his position as chairman and chief executive at MF Global Holdings Ltd. on Nov. 4 while the FBI conducts an ongoing investigation into $633 million of client money that is unaccounted for at the options and futures firm.

Corzine joined the Princeton faculty for a one-year term as a visiting lecturer during the 2010-2011 academic year. As New Jersey governor, Corzine also served as an ex officio member of the University’s Board of Trustees.

His home department while at the University, the Wilson School, declined to comment on Corzine’s resignation and the ongoing investigation.

“I feel great sadness for what has transpired at MF Global and the impact it has had on the firm’s clients, employees and many others,” Corzine said in a statement. “I intend to continue to assist the company and its board in their efforts to respond to regulatory inquiries and issues related to the disposition of the firm’s assets.”

Corzine, who will not seek the $12 million severance package, has hired defense lawyer Andrew Levander, a partner at the Dechert LLP law firm. Levander did not respond to a request for comment.

MF Global filed for Chapter 11 bankruptcy on Oct. 31 after it bet $6.3 billion on European sovereign debt. This makes it the largest U.S. casualty of Europe’s debt crisis.

Prior to filing for bankruptcy, the company’s credit ratings and shares dropped. There were also signs that some of its customer accounts that were supposed to be segregated from the rest of the business had been affected.

“MF Global informed the regulators that the transaction had not been agreed to and reported possible deficiencies in customer futures segregated accounts held at the firm,” the U.S. Securities and Exchange Commission and the Commodity Futures Trading Commission said in a joint statement.

Despite Corzine’s resignation, it is still unknown whether any management misconduct was involved. The officers and directors of the brokerage will be subpoenaed, and the FBI investigation is looking into the company’s accounts at JPMorgan Chase, where the missing client money is allegedly contained.

Corzine joined MF Global in March 2010 after losing reelection to current New Jersey governor Chris Christie and served as chairman concurrently with his one-year lecturer post at the University.

He previously served as the head of Goldman Sachs.