News Release

CME Group and NYMEX Extend Exclusive Negotiating Period until March 15, 2008

Mon Feb 25 2008

CHICAGO and NEW YORK, Feb. 25 /PRNewswire-FirstCall/ -- CME Group Inc. (NYSE: CME)(NASDAQ: CME) and NYMEX Holdings, Inc. (NYSE: NMX) today announced that they have agreed to extend the 30-day exclusive negotiating period regarding CME Group's potential acquisition of NYMEX until March 15, 2008.

The potential transaction remains subject to completion of due diligence, negotiation of terms of a definitive agreement and approvals of the Boards of Directors of both companies. There can be no certainty that any agreement will be entered into or as to the terms of any agreement. There will be no further comment until an agreement is reached or the discussions are terminated.

About CME Group

CME Group (http://www.cmegroup.com/) is the world's largest and most diverse exchange. Formed by the 2007 merger of the Chicago Mercantile Exchange (CME) and the Chicago Board of Trade (CBOT), CME Group serves the risk management needs of customers around the globe. As an international marketplace, CME Group brings buyers and sellers together on the CME Globex® electronic trading platform and on its trading floors. CME Group offers the widest range of benchmark products available across all major asset classes, including futures and options based on interest rates, equity indexes, foreign exchange, agricultural commodities, and alternative investment products such as weather and real estate. CME Group is traded on the New York Stock Exchange and NASDAQ under the symbol "CME."

About NYMEX Holdings, Inc.

NYMEX Holdings, Inc. (NYSE: NMX) is the parent company of the New York Mercantile Exchange, Inc., the world's largest physical commodities exchange, offering futures and options trading in energy and metals contracts and clearing services for more than 350 off-exchange contracts. Through a hybrid model of open outcry floor trading and electronic trading on the CME Globex® and NYMEX ClearPort® electronic platforms, NYMEX offers crude oil, petroleum products, natural gas, coal, electricity, gold, silver, copper, aluminum, platinum group metals, emissions, and soft commodities contracts for trading and clearing virtually 24 hours each day. Further information about NYMEX Holdings, Inc. and the New York Mercantile Exchange, Inc. is available on the NYMEX website at http://www.nymex.com/.

Forward-Looking Statements

This press release may contain forward-looking information regarding CME Group and NYMEX Holdings that are intended to be covered by the safe harbor for "forward-looking statements" provided by the Private Securities Litigation Reform Act of 1995. These statements include, but are not limited to, whether an acquisition of NYMEX Holdings by CME Group will occur and the terms and conditions of any such acquisition. You should not place undue reliance on forward-looking statements, which speak only as of the date of this press release. Except for any obligation to disclose material information under the Federal securities laws, CME Group and NYMEX Holdings undertake no obligation to release publicly any revisions to any forward-looking statements to reflect events or circumstances after the date of this press release.

CME-G

SOURCE: CME Group Inc.; NYMEX Holdings, Inc.

CONTACT: press inquiries, Allan Schoenberg of CME Group Inc.,
+1-312-930-8189, news@cme.com; or Anu Ahluwalia of NYMEX Holdings, Inc.,
+1-212-299-2439; or investors, John Peschier of CME Group Inc.,
+1-312-930-8491; or Keil Decker of NYMEX Holdings, Inc., +1-212-299-2209

Web site: http://www.cme.com/
http://www.nymex.com/

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