Hi Kevin,
Thanks for your quick and helpful reply.
So if I understand you correctly, without specifically targeting a region using web master tools and using a region agnostic tld such as .com tells Google that this is our Global Site. As long as we leave our global site un-targeted and the regional sites targeted would be the most effective way to ensure non-regional traffic is driven to our global site.
As our sites are not multilingual, maybe the Brazilian example was not the best - however I was referring to English based queries.
With regards to your last point, no each site is a separate domain.
Thanks again for you help and advise.
Many thanks,
Jason