See Who Your Google Competitors are Globally | Google Global Firefox Extension

If you get fed up with being redirected back to Google.ca when you are trying to search for your competitors on Google.com or Google.co.uk or Google.com.au you can try out this the  Google Global Firefox Extension.

Not only will you be able to see your organic competitors but you will also see your PPC competitors as well. There are paid tools that can do the same thing but why pay when you can use this tool for free.