Hi
You clearly need professional legal advice.
I am not a copyright expert but yes there is the possibility that copyright exists in the name.
How on earth do you know there is no trade mark? You searched the trade mark register of every country in the world? You must have a lot of cash. You know for certain the person in question has no common law rights in the name? You will note that it is a tenet of the UDRP that the domain name extension does not materially affect the trade mark - i.e. xxx.com and xxx.net are not held to be different by virtue of what is after the DOT so why would you think that simply removing the .com from a potential trade mark makes it different?
No offence - but your assumptions could get you in trouble here. If you've been contacted already, take advice from a professional.
