IBM has provided more information about the countersuit it has filed against the SCO Group, and has revealed backing from Novell.

In a statement Big Blue said: "IBM is seeking compensatory and punitive damages and an injunction requiring SCO to refrain from misrepresenting its rights, and to cease further infringement of IBM's patents."

It added in a statement to vnunet.com: "SCO has improperly claimed the right to revoke IBM's Unix licence, despite the fact that IBM's contract expressly provides that IBM's rights are irrevocable and that Novell, which is a party to the agreement under which IBM obtained an irrevocable and perpetual Unix licence, agrees that SCO cannot terminate IBM's licence and has exercised its right to waive this claim."

Ovum principal consultant, Gary Barnett, said Novell's support paved the way for arguments to be presented in court, and that IBM's relatively small number of countercharges was probably just the start.

"I expect to see an iterative raising of more issues in a very well-defined and pre-planned strategy," he said.

"We can expect IBM to significantly raise the pace now. It is sending a clear signal that it is not going to cave in quietly and pay off SCO."

IBM also claims SCO has infringed four IBM patents and violated the GNU General Public Licence (GPL) that covers Linux usage.

The four patents relate to SCO's commercially available UnixWare and Open Server Unix operating system products, and SCO Manager and Reliant HA clustering software.

But SCO has hit back, saying: "We view IBM's counterclaim filing today as an effort to distract attention from its flawed Linux business model. It repeats the same unsubstantiated allegations made in Red Hat's filing earlier this week.

"If IBM was serious about addressing the real problems with Linux, it would offer full customer indemnification and move away from the GPL.

"IBM urges its customers to use non-warranted, unprotected software. This software violates SCO's intellectual property rights in Unix, and fails to give comfort to customers going forward in use of Linux.

"If IBM wants customers to accept the GPL risk, it should indemnify them against that risk."

Regarding IBM's claim of patent infringement, SCO said: "SCO has shipped these products for many years, in some cases for nearly two decades, and this is the first time that IBM has ever raised an issue about patent infringement in these products."