In today's world, most companies span several regions and sell around the world. As Foolish colleague Morgan Housel notes, 10 years ago, less than a third of S&P 500 revenue growth came from abroad. Today, that area makes up half of the S&P 500's growth.

And that number is growing. The truth is, investors regularly underestimate how much demand comes from abroad. More importantly, for large, multinational corporations that have already established a presence in their home markets, much of their future growth comes from abroad.

With that in mind, today we're looking at Bank of America (NYS: BAC) . We'll examine not only where its sales and earnings come from, but also how its sales abroad have changed over time.

Where Bank of America's sales were five years ago
Five years ago, Bank of America produced 89% of its sales within the United States.

Source: S&P Capital IQ.

Source: S&P Capital IQ.

Where Bank of America's sales are today
Today, the United States is still Bank of America's largest market, but its influence is shrinking.

Source: S&P Capital IQ.

Source: S&P Capital IQ.

Of course, beyond just sales, banks can be global operations through their exposure to other regions by way of their credit and trading portfolios. Let's look at Bank of America's largest non-U..S regional exposures across the past two years.

Source: Bank of America 10-K.

Not surprisingly, the bank reduced its exposure to Europe last year, as concerns grew about the sovereign-debt situation in Italy, Portugal, Ireland, and Greece. Meanwhile, Bank of America's exposure in other regions held relatively firm.

Overall, Bank of America's exposure to emerging markets is relatively light: 60% of emerging-market exposure is in the Asia-Pacific region, with India being the largest market at about $10.5 billion in exposure.

Competitor checkup
One last point to check is how Bank of America's footprint compares with some of its peers.

Source: S&P Capital IQ. Results for most recently reported fiscal year.

Among its peer group, Bank of America remains the most levered to the United States market despite its overseas growth in the past half-decade. JPMorgan Chase shares the most similar profile to Bank of America, though it has higher sales in Europe and less in the Asia-Pacific region.

I recently read The Growth Map: Economic Opportunity in the BRICs and Beyond, by Jim O'Niell, creator of the BRIC acronym and chairman of Goldman Sachs Asset Management. Naturally, his view on Goldman Sachs' opportunities in Asia veered toward its smaller -- relative to its trading unit -- asset-management group, but I was struck by how quickly he viewed its Asian operations as becoming pre-eminent. I have to imagine that with all the wealth being created in these markets and O'Neill - a man who clearly believes foremost in the BRIC story - at the helm, Goldman's push into Asia will be among the stronger of the U.S. banks.

Finally, Citigroup is among the most globally diversified of the large banks. As one small example, Citigroup recently became the first Western bank to receive regulatory approval to issue credit cards under its own name in China. While China will always be a stubbornly difficult environment for foreign financial firms, Citi is positioned for greater growth across Asia.

Keep searching for global opportunities
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At the time thisarticle was published Eric Bleekerowns shares of no companies listed above. You canfollow him on Twitterto see all of his technology and market commentary. The Motley Fool owns shares of JPMorgan Chase, Bank of America, and Citigroup.Motley Fool newsletter serviceshave recommended buying shares of Goldman Sachs. Try any of our Foolish newsletter servicesfree for 30 days. We Fools don't all hold the same opinions, but we all believe thatconsidering a diverse range of insightsmakes us better investors. The Motley Fool has adisclosure policy.

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