A few years ago, I was a sole distributor for a product in Australia (let's say the product I was selling was called ABC) and registered the business name ABC Aust to help my business efforts. Our relationship subsequently soured and I no longer distribute that product. However, the overseas company I was dealing with has just found out that I still hold the Australian-ised company name of their product and are demanding that I hand it over. The product name is trademarked overseas but not a trademark here in Australia. It was an available business name when I got it - so do I have to hand it over? Any help greatly appreciated.