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Thanks Russ, Our target geo locations include not only UK though London is a priority targeting. We have some sections focused on other regions and that's the main reason why I don't want to set up region in WMT. For most important kwds we have first positions in local search which give us significant traffic. I want to be sure that we will keep the positions before making any changes.

I'm looking at the URL and going off of memory -- I think that's just for the search appliance and not for Google in general. You might want to look further at the documentation, but I think that's just for their search appliance and not the web as a whole.