As the title suggests, there is a way to inform Google about different sections on your website/brand that are targeted to different parts of the world. You can inform Google to treat different sections within a website based on what you declare in the Google Webmaster Tools (GWT) console (if you don’t have one then get it, use your Google ID, it’s free).
Google currently automatically targets region based on TLD (top level domain). But did you know you can inform Google if you have a subdomain for a particular country and that country only. But what’s even better for some is you can make the same declaration for a sub-folder. This is useful for those who can’t get, say, a Arabic domain but have content relevant to a market that speaks Arabic. You can register a subdomain for that part of your website and target Arabic speaking countries in GWT.
I’m not certain, however, since I haven’t tested myself, whether it’s better to have a country specific TLD over a sub-domain or sub-folder when it comes to rankings. Google will differentiate based on the sites you ‘register’ in GWT, but I haven’t heard if one is better than the other (even by a marginal amount).
You also have to make a consideration what would be a better choice of site infrastructure based on your brand as well. Would it better for your brand to have a country specific TLD (a completely different website)? Or would it work just as well to have a subfolder (all under, say, a .com)?