Stock Exchange Announcement, August 13, 2007 Change in holding in OMX Borse Dubai Limited announced to Finansinspektionen on August 10, 2007, that they have acquired 5,880,130 of the shares in OMX AB, equivalent to 4,9 percent of the current 120,640467 outstanding shares and votes. In addition Borse Dubai Limited announced that they have made an Option Agreement on 27,280,791 of the shares of OMX AB. If this Option Agreement is exercised, the total holding of Borse Dubai Limited in OMX AB would amount to 33,160,921 shares, equivalent to 27.5 percent of the current outstanding shares and votes. For further information, please contact: Jakob Håkanson, Vice President, Investor Relations, OMX +46 8 405 60 42 About OMX | OMX is a leading expert in the exchange industry. The common offering from OMX Nordic Exchange in Helsinki, Copenhagen, Stockholm, Iceland, Tallinn, Riga and Vilnius, comprises over 800 companies including its alternative market First North. OMX provides technology to over 60 exchanges, clearing organizations and central securities depositories in over 50 countries. OMX is a Nordic Large Cap company in the Financials sector on the OMX Nordic Exchange. For more information, please visit www.omxgroup.com.