September 14, 2010 at 14.35

Announcement pursuant to Securities Act Chapter 2, Section 10 

F-Secure Corporation has today been informed by OP-Keskus osk that the holding
of OP-Keskus in F-Secure has fallen below 5% (1/20) and is currently 4.9%,
after being, on the basis of their previous announcement, 5.013% on September
7, 2010. 

1. The company: F-Secure Corporation

2. The date of change in holding: September 14, 2010 

3. 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         
4.281.016 shares, 2.719% 

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

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

Totally 7.716.203 shares, 4.9% 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