Microsoft on Tuesday closed its acquisition of Sybari Software and said the anti-virus and anti-spam vendor would remain a wholly owned subsidiary but that Microsoft would discontinue Sybari’s line of Unix and Linux products.

The company will continue to support all the anti-virus engines that work with Sybari’s server-based products. Sybari did not produce its own anti-virus engine instead it provided virus signature updates using the engines from other vendors including Sophos, Computer Associates and Kaspersky Labs, which are now listed among the 25 anti-virus partners on Microsoft’s Web site. Microsoft also will integrate its own anti-virus engine, which it acquired in 2003 in its acquisition of GeCad.

Microsoft plans to continue to support Sybari’s Antigen for Lotus Notes on the Windows platform, but will not sell Antigen versions for Unix and Linux platforms. However, Microsoft will continue to offer Sybari products under existing pricing and licensing terms and support existing users on non-Windows platforms.

“We will continue to support those products for the life of the contracts,” says Amy Roberts, director of product management in Microsoft’s security and technology business unit.

Sybari’s Antigen also works with Microsoft Exchange messaging server, as well as Office SharePoint Portal Server 2003, Windows SharePoint Services and Live Communications Server 2005. There is also an Antigen version for SMTP Gateways.

Microsoft has been working to integrate Sybari’s Advanced Spam Manager with Exchange’s Intelligent Message Filter technology, according to Roberts.

“Probably as we move forward we will continue to see this type of integration and there may be some additional work, but since the deal just closed a lot of that work will be getting the various engineering teams together to see what makes the most sense,” says Roberts.

Microsoft also has management integration work to do to mesh its Dynamic Systems Initiative with Sybari’s management platform, which uses a single console to manage its software on the network. The likely intersection would be with Microsoft’s System Center brand of management software that now includes System Management Server, Microsoft Operations Manger, Data Protection Manager and Reporting Manager.