Berkshire has invested in over 100 companies over two decades. Historically, our investment activity has been concentrated around consumer products and retail, business services, transportation, energy, industrial manufacturing, communications and related fields. Each of these sectors has been exceptionally successful for us. As meaningful opportunities similarly present themselves in the future, we will continue to make investments in these areas.
Of course, it's a great advantage to understand an industry intimately, and to make investments based on that understanding. But we also continue to consider exciting opportunities in fields that are new to us knowing full well that some of our most interesting investments have been made in industries in which we had no previous activity.
We also seek to find quality investments wherever they may be. While our historical focus has been centered on the U.S. and Canada, we have completed transactions in Europe and even as far as Australia and New Zealand. We especially like working with our portfolio companies to pursue international expansion, be it through organic growth opportunities or the acquisition of complimentary offshore operating companies.