Notice 543 November 13, 2008 CME Group to Expand Listing of Natural Gas Options and Natural Gas Look Alike Options Through 2021 Beginning on Sunday evening, December 7, 2008 (for trade date Monday, December 8, 2008), CME Group will expand the listing of its American Style (ON) Natural Gas Options as well as European Style (LN) Natural Gas Look Alike Options with consecutive monthly contract months through December 2021. With the expiration of the December 2009 option, an entire new calendar year (2022) will be added. The expanded option listings will be on both the NYMEX Division trading floor for open-outcry trading, as well as for clearing on NYMEX Division ClearPort®. The expanded contract months will not be listed on Globex®. Currently the Exchange lists Natural Gas options for consecutive months for the balance of the current year and eight additional years. Should you have any questions or require any further information, please contact ExchangeInformation@cmegroup.com.