Managed messaging security service provider Postini Monday announced plans to integrate ScanSafe’s hosted Web filtering service into its own offerings.

Slated for availability late in the third quarter, the service will be branded Postini Web Content Manager and will be integrated with the company’s existing security offerings for e-mail and instant-messaging communications, says Andrew Lochart, Postini’s senior director of marketing.

The service will provide Postini customers with URL filtering and protection from viruses and spyware that are often picked up when users visit Web sites. Customers can use the service to block access to Web sites known to be dangerous or those that fall outside of the organization’s Internet usage policies, say company officials.

By blocking sites known for downloading malware onto visitors’ PCs, companies can cut down significantly on security threats entering their organization, they say. Companies can also block access to employees’ Web e-mail accounts that often fall outside the reach of corporate spam and phishing filters.

Much like current Postini customers’ SMTP traffic travels through the company’s data center for scanning, customers’ HTTP and FTP traffic will flow through ScanSafe’s data center. In order to prevent latency, ScanSafe has developed a network of servers in its data centers that process in a massively parallel manner so that the different elements comprising a Web page are processed at once and sent back to the user, officials say.

Administrators will be able to leverage the same console they use for managing Postini’s IM and e-mail services to control the Web service.

MessageLabs, which competes with Postini, also resells ScanSafe’s Web filtering service.

Pricing for the new Postini service has not yet been announced.