TO:	ALL CLEARING PARTICIPANTS
FROM:	CLIENT SERVICES AND SUPPORT
DATE:	May 1, 2006
SUBJECT:	Chicago Climate Exchange Margin Rate Change

The following margin intervals are effective at the close of business on Monday May 01, 2006:

Contract	From	To
May 06 Sulfur Dioxide	$2,600	$3,500

Should you have any questions, please call or e-mail one of the following Client Services and Support Representatives: