The privately held Massachusetts, US-based company sells appliances that probe computer networks, providing security and compliance analysis.

EMC's latest acquisition, expected to close late Monday, underscores the growing importance of security technology to the storage vendor. Also on Monday, EMC announced that it had completed its $2.1 billion (£1.2bn) purchase of RSA Security, which will form the basis of a new RSA-branded security division within the company.

Former RSA CEO Art Coviello will head up this division, which will absorb the Network Intelligence business unit, EMC said in a statement.

With these latest acquisitions, EMC hopes to be able to sell security as part of a broader product portfolio, said Joe Tucci, EMC's chairman, president and CEO. "It's becoming critical that security move beyond a point product solution," he said.

Analysts say security companies will find it increasingly difficult to go it alone, with technology giants such as Microsoft, Cisco and IBM moving quickly to add security features to their broader product platforms. Just last month, IBM said it would spend $1.3bn (£695m) to acquire managed security vendor Internet Security Systems (ISS).