Hi Subin,
I would actually ask WHY do you want to suppress the creation of the Interaction Record? Doing so is actually not recommended as a lot of functionality in the Interaction Center relies on the IR including reporting; creating follow-on business transactions; and INTO/INTA linking of emails, service requests, solutions/knowledge articles, etc.
A better idea would just be to remove the IR object from the screen so that agents don't see it and don't need to fill it out, but still allow it to be created in the background.
You can find a little more info in this blog post by Gert Tackaert, "Everything you need to know about the Interaction Record..."
Regards,
John