Item 1.01 Entry into a Material Definitive Agreement

On October 10, 2008, Chicago Mercantile Exchange Inc. ("CME"), a wholly owned subsidiary of CME Group Inc., entered into a renewal of its 364-day revolving credit facility (the "Credit Facility") with each of the banks from time to time party thereto and the Bank of Montreal, as administrative agent, the JP Morgan Chase Bank, N.A., as collateral agent, and BMO Capital Markets, as lead arranger. The Credit Facility is for a line of credit up to $600 million to provide temporary liquidity to CME in circumstances where CME is entitled to use the security deposits and performance bonds of its clearing members to satisfy any outstanding obligations of any defaulting clearing member to CME as provided in the CME Rulebook and in circumstances where problems exist with a money transfer system that affect CME's operations. The Credit Facility is collateralized by clearing firm security deposits and performance bonds held by CME. The Credit Facility also provides the Board of Directors of CME to authorize an increase in the line of credit from $600 million to $1 billion, provided, however, the participating banks are not obligated to comply with our request.

The foregoing description of the Credit Facility is only a summary, does not purport to be complete and is qualified in its entirety by reference to, and should be read in conjunction with, the complete text of the Credit Facility, which is filed as Exhibit 10.1 hereto and is incorporated herein by reference.

Item 9.01 Financial Statements and Exhibits.

(d) Exhibits.

Credit Agreement, dated as of October 10, 2008, between Chicago Mercantile Exchange Inc. and each of the banks from time to time party thereto and the Bank of Montreal, as administrative agent, JP Morgan Chase Bank N.A., as collateral agent, and BMO Capital Markets, as lead arranger.

---