Symantec signed an agreement yesterday to acquire antispam vendor Brightmail for $370 million to complement its range of gateway security software.

Symantec said that anti-spam technology is key to its product lineup because spam has become one of the most severe threats to individuals and enterprises today.

Brightmail uses multiple proprietary technologies, a globally deployed detection network, and a dynamic rule delivery mechanism to identify and filter unsolicited or unwanted electronic messages. In April, Brightmail filtered 96 billion email messages and reported that 64 per cent of the email that passed through its filters was spam.

The acquisition is the next step in an established partnership in that Brightmail already has integrated Symantec's anti-virus technology into its infrastructure.

Symantec made a strategic investment in Brightmail in July 2000 and currently holds an approximately 11 per cent equity stake in the company.

In April 2004, Brightmail filed a registration statement for an initial public offering, but its board of directors and stockholders concluded the combination with Symantec was a more favourable strategic alternative.

Brightmail chairman Eric W Spivey, said: "This is a tremendous win for Brightmail. The combination of the two companies will be an impressive force in the security space."