Stock Exchange Announcement, February 26, 2008                                  

Change in holding in OMX   
Investor AB (Investor) announced today that they have decreased their holding in
OMX AB below ten (10) percent on February 22, 2008. The holding in OMX AB was   
decreased with 12,950,507 shares. Thereafter, Investor's holding in OMX AB is   
now 0 shares. The share capital of OMX AB consists of 120,640,467 shares.       

For further information, please contact:                                        
Jakob Håkanson, Vice President, Investor Relations, OMX    +46 8 405 60 42