Cisco has announced plans to buy privately held ScanSafe, a maker of software-as-a-service (SaaS) Web security services for enterprises and small-to-midsize businesses, for $US183 million.

The ScanSafe acquisition dovetails with Cisco's 2007 purchase of on-premise Web security appliance maker IronPort. With these two deals, Cisco will have SaaS and premises-based Web security offerings.

Cisco says it expects Web security to be a $2.3 billion market by 2012.

ScanSafe's service will be integrated with Cisco's AnyConnect VPN Client. Cisco says ScanSafe's global data centers and multi-tenant architecture will allow Cisco to provide cloud-security services for customers worldwide.

Under terms of the agreement, Cisco will pay approximately $183 million in cash and retention-based incentives. The acquisition is subject to various standard closing conditions and is expected to close in the second quarter of Cisco's fiscal year 2010.

Upon close of the acquisition, ScanSafe will become part of Cisco's Security Technology Business Unit, reporting to Vice President and General Manager Tom Gillis.