Google has rebranded its Postini subscription-based security service, slashed the price by 40%, and added a new option that protects employees working on wireless networks outside their companies' firewalls.

Google Web Security for Enterprise is priced at $36 a year per user, down from $59 for the Postini service. Google acquired Postini, which offers a wide range of online security and compliance services, for $625 million last July. The new optional remote security service is $12 a year per user.

The rebranding and the price reduction on the main service is a continuation of Google's efforts to grow its presence in the business market with hosted, low-cost software and services.

Google Web Security provides real-time scanning for viruses and spyware, blocks harmful Web sites, and also provides administrators with tools to create Web filtering policies, according to Google. The service will monitor users' online activity and provide administrators with comprehensive reports, Google said.

The additional remote service -- designed for those who work out of the home, or use Wi-Fi hotspots in cafes, hotels, and client sites -- automatically encrypts all Web traffic when the user connects to a public network. This can eliminate the need for employees to use their companies' VPNs as an extra security measure when exchanging e-mail or using the Web, according to Google. The services fall within the company's Google Apps division.

"One of the benefits of Google Apps is the protection it provides for communication and collaboration within businesses," said Scott Petry, director of product management, in a statement. "Now companies can extend that protection to more of their users' Internet activities, whether they're surfing the Web at the office or the airport."

The service is based primarily on the technology of security-as-a-service vendor ScanSafe, which has an existing relationship with Postini.