The last move, which saw IBM being informed it no longer has the right to use SCO licensed code in its AIX operating system, is of great concern to existing and potential users.
SCO said it will prosecute individual companies for the licence fee, even though it may have been purchased through IBM.
The CUA contacted IBM on behalf of its members to ask for reassurance that any customers faced with a SCO claim will be supported and compensated by IBM. The CUA expects to be contacted shortly with IBM's response.
"Our members have purchased their licences in good faith. Any successful prosecution by SCO could result in large amounts of money being owed," said Ray Titcombe, chairman of the CUA.
"We have asked IBM to recompense any financial or operational loss that any company faces as a result of the SCO challenge."
Titcombe's letter elicited a bland response and the debate between IBM and the CUA is now off the record.