September 7, 2010 at 16.10

Announcement pursuant to Securities Act Chapter 2, Section 10 

F-Secure Corporation has today been informed by OP-Keskus osk that the holding
of OPK-Keskus in F-Secure has exceeded 5 % (1/20) and is currently 5.013%. 

1. The company: F-Secure Corporation

2. The date of change in holding: September 7, 2010 

3. The shareholders and their proportions of shares and voting rights in
F-Secure Corporation: 

Pohjola Vakuutus Oy, register number 1458359-3   
125.000 shares, 0.079% 

A-Vakuutus Oy, 1715947-2   
18.968 shares, 0.012% 

OP-Henkivakuutus, 1030059-2
186.498 shares, 0.118%

OP-Rahastoyhtiö's funds, 0743962-2 

OP-Delta, 1102395-3         
4.459.530 shares, 2.832% 

OP-Suomi Pienyhtiöt, 1753300-6       
2.580.418 shares, 1.639% 

OP-Focus, 1753298-6        
524.303 shares, 0.333% 

Totally 7.894.717 shares, 5.013% of share capital and voting rights.   

4. Shareholder's name and register number: OP-Keskus osk, 0242522-1

F-Secure Oyj
Taneli Virtanen
CFO

For more information, please contact:
F-Secure Corporation
Mervi Pohjoisaho, IR, tel. +358 40 535 8989