Caledonian,
I think you will find ten years ago the UK was full of Swedish and Norwegian registered aircraft doing exactly this.
All using second hand equipment.
Keyvon,
Isn't the Jetx owned and operated by the Icelandic firm (can't remember the name) on long term lease to Jetx and since been farmed out to other carriers. Certainly the crew are Icelandic. Can you have an Italian owned aircraft in a foreign reg?