cme @

Chicago Mercantile Exchange
20 South Wacker Drive 312/930.1000 tel
Chicago, IL 60606-7499 312/466.4410 fax

www.cme.com

June 21, 2004

Ms. Eileen Donovan f
Office of the Secretariat

Commodity Futures Trading Commission :
Three Lafayette Centre ;
1155 21* Street, N.W.
Washington, D.C. 20581

RE: Section 5c(c) and Regulation §40.6 Submission - Exchange Certificatior:-of
Amendment to Block Trades. CME Submission #06-54.

Dear Ms. Donovan:

Chicago Mercantile Exchange Inc. (““CME” or “Exchange”) hereby submits, pursuant to
Section 5c(c) of the Act and Regulation §40.6 thereunder, notification of amendments to CME
Rule 526 - Block Trades.

On June 21, 2006, pursuant to Rule 230.j., the Exchange’s Chairman, CEO and President,
per their authority delegated by the Board of Directors of the Exchange per Rule 230,j., jointly
approved the changes to the reporting period for block trades in CME Housing futures and
options. Exchange members, clearing firms, and other market participants will be notified of this
information via a Special Executive Report dated June 22, 2006, and CME Update 06-07, dated
July 3, 2006.

CME certifies that these actions neither violate nor are inconsistent with any provision of
the Commodity Exchange Act or rules thereunder.

Effective Thursday, June 22, 2006, Rule 526 —- BLOCK TRADES, shall be amended such
that the Reporting Period for Block Trades in CME Housing futures and options contracts will
be extended from five (5) to fifteen (15) minutes. Please refer to the Block Trading FAQ on the
CME website for frequently asked questions and answers concerning block trading and the
minimum thresholds for executing blocks at www.com.com/files/blocktrad.pdf.



Ms. Eileen Donovan
June 21, 2006
Page 2 of 2

The changes to Rule 526 to reflect this update are shown below, with additions
underlined.

526. BLOCK TRADES

Notwithstanding Rule 520, the Board or a committee appointed by the Board shall, from time to time,
determine the minimum thresholds for, and the Exchange products in which, block trades (privately
negotiated transactions) shall be permitted. The following shall govern block trades:

[Sections A. through E. are unchanged]

F. The seller must ensure that each block trade is reported to the Exchange within five minutes of the
time of execution; except that block trades in Eurodollar, Housing, and Weather futures and options
must be reported within fifteen minutes of the time of execution. The report must include the contract,
contract month, price, quantity of the transaction, the respective clearing members, the time of
execution, and, for options, strike price, put or call and expiration month. The Exchange shall
promptly publish such information separately from the reports of transactions in the regular market.

[Remainder of the rule is unchanged]

If my staff or I may assist you, please do not hesitate to contact Sayee Srinivasan at 312-
454-5205 or ssriniva@cme.com, or myself at 312-466-7469 or jlab@cme.com. We would be
appreciative if you could please reference our CME Submission Number 06-54 in any related

correspondence.

Sincerely,

’ _

John W. Labuszewski, Managing Director
Research & Product Development

ce: Thomas M. Leahy, Jr., CFTC Division of Economic Analysis

/ss