Stock Exchange Announcement, September 20, 2007 Change in holding in OMX Qatar Holding LLC (Qatar Holding) announced that they have increased their holding in OMX AB. The holding in OMX AB is now 9.98 percent of the shares and votes of OMX AB. OMX AB has altogether 120 640 467 shares. For further information, please contact: Jakob Håkanson, Vice President, Investor Relations, OMX +46 8 405 60 42