Tuesday, February 8, 2005 Microsoft has announced that it plans to purchase antivirus firm Sybari Software in order to expand its market within the computer security market. The takeover comes after Microsoft purchased Romanian security firm GeCad in 2003 and two months after an announcement that it is to acquire anti-spyware vendor Giant-Company Software.

Sybari is a private company based in East Newport, New York that develops antivirus software which can be used with Microsoft’s Exchange software, as well as with the Lotus Notes system.

This takeover is seen by analysts to be hostile move on Microsoft’s part, as it places the software giant in direct competition with market leaders Symantec and McAfee. Sterling Auty, an analyst with JP Morgan, told Reuters that he estimated that Microsoft could be competing for up to five percent of Symantec’s business and up to eight percent of McAfee’s revenue.

Microsoft’s shares rose $0.10 at midday to $26.26, while both McAfee and Symantec shares fell.