Two banks and an insurance company have accepted Microsoft's offer of technical support for Novell's Suse Enterprise Linux, even though one of the three, Credit Suisse Group, does not yet use it.

Novell and Microsoft announced a deal last month to "bridge the divide between open-source and proprietary-source software." Under the deal, Microsoft promised not to file patent lawsuits against Novell customers. It will also spend $440 million on sales, marketing and licence fees in support of Novell's Suse Linux. The two companies will also work together to help customers integrate their competing operating systems.

As part of its marketing support, Microsoft agreed to distribute "subscription certificates", each one entitling customers to technical support from Novell for a server running Suse Enterprise Linux. Microsoft intends to distribute around 70,000 of the certificates a year for the next five years. Customers have already activated 16,000 of the certificates in the seven weeks they have been offered, Microsoft said.

The companies declined to put a price on the certificates, but Microsoft's general manager for customer advocacy and licensing, Susan Hauser, warned: "Don't assume that we're giving them away."

Credit Suisse is a new customer for Novell, said Susan Heystee, vice president of global strategic partners at Novell, and responsible for Novell's new relationship with Microsoft. "They are making a commitment to deploying Suse Linux in their virtualisation environment," Heystee said.

Microsoft also named Deutsche Bank and AIG Technologies, part of insurance company American International Group, as among the customers that have activated Suse Linux subscriptions. None of the companies would say how many certificates were involved.

Deutsche Bank already uses Microsoft software and Suse Linux. Hauser hinted that Microsoft is not the one losing servers to Suse at Deutsche Bank. "They may not be completely a Suse shop in all parts of their organisation," she said.

Help integrating open source and proprietary software is the most important aspect of the deal for Deutsche Bank: the certificate for support for Linux takes a back seat. "This is not about the certificates," said a spokesman for Deutsche Bank. "This enables us to integrate these systems," he said. An AIG Technologies spokesman also confirmed that his company had struck a deal with Microsoft, but declined to comment further.

In promising not to sue Novell's Linux customers for patent infringement, Microsoft is trying to portray other open-source systems as a risk for businesses. Hauser explained: "Customers were often very confused as to what rights they had from an intellectual property standpoint. They didn't want to have to figure it out, so we figured it out for them."