Cisco said that it plans to acquire privately held software-as-a-service (SaaS) web security provider ScanSafe for around $183m in cash and retention-based incentives, in a move to broaden its existing on-premise web security offering and expand cloud-based service opportunities.

ScanSafe, which is based in London and San Francisco, provides web security service that scans all web requests for malicious content and offers protection from zero-day threats.

Tom Gillis, vice president and general manager of security technology business unit (STBU) at Cisco, said: With the acquisition of ScanSafe, Cisco is executing on our vision to build a borderless network security architecture that combines network and cloud-based services for advanced security enforcement. Cisco will provide customers the flexibility to choose the deployment model that best suits their organisation and deliver anytime, anywhere protection against web-based threats.

By acquiring ScanSafe, Cisco is building on its acquisition of on-premise content security provider IronPort. The acquisition brings together the Cisco IronPort web security appliance and ScanSafe’s SaaS web security service. This combination will expand Cisco’s security portfolio to offer on-premise, hosted, and hybrid-hosted web security offerings.

Under the completion of the transaction, ScanSafe’s service will be integrated with Cisco AnyConnect VPN Client, the newest virtual private network (VPN) product from Cisco, to provide secure mobility offering. The ScanSafe team will become part of Cisco’s STBU, reporting to Gillis.

Cisco said that the ScanSafe’s global network of carrier-grade data centres and multi-tenent architecture will enhance its ability to provide new cloud-security services for customers worldwide.

The acquisition marks the latest of several initiatives undertaken by Cisco. Earlier this month, Cisco has agreed to buy IP-based mobile infrastructure products provider Starent Networks for $2.9 billion, in a move to expand its mobile internet offerings for service providers. It also bid $3 billion to acquire video conferencing firm Tandberg.

The transaction is expected to close in the second quarter of fiscal year 2010, subject to various standard closing conditions.