Buying .com.au domain when .com is taken?

Hi i'm looking to buy a .com.au domain which is available but the .com domain is taken and has a website on it.

I was wondering if there is any risk of potential legal issues of the .com company even though it's registered in another country?

Is there anything you can check e.g. trademark, or anything to ensure no potential issues.

Cheers.

Only if the holder of the .com have international trademark rights

can't you place a (-) or to shorten your domain, or even to mispell it?

try variations of it