U.S. investors should diversify their portfolios with companies located in foreign countries. It's now simple and easy to buy exchange traded funds of foreign companies that pay dividends. Because their earnings are not denominated in U.S. dollars, this is a good way to reduce currency risk. Collect income that does not depend on a strong U.S. dollar.

The United States stock market is the largest in the world, but certainly not the only important one. Much of the world's economic activity, and many of its public companies that pay stock dividends, are traded in Europe, Asia, the Middle East, and South America.

The greatest growth potential lies in the developing world. If U.S. investors restrict their portfolios to Wall Street they cannot profit from the rest of the world.

However, it's not easy for the average small investor to invest in companies listed in London and Tokyo, let alone Brazil and China.

If investors want to receive dividends from companies around the world, it's difficult just to find the best ones.

However, four exchange traded funds (ETFs) now make this simple and easy for U.S. investors.

The first is PowerShares International Dividend Achievers Portfolio: PID. PID tracks the Mergent International Dividend Achievers Index. This is a list of all companies outside the United States which have raised their dividends every year for at least the past five years, and which trade on the New York Stock Exchange, American Stock Exchange, or NASDAQ.

The top countries represented by this ETF are Canada, The United Kingdom, Japan, Bermuda, and Mexico. It holds ninety different companies. The top three companies it owns are Grupo Aeroportuario del Sureste S.A.B. de C.V. (ADS), Tsakos Energy Navigation Ltd., and BP PLC (ADS). Its distribution yield is 6.25%.

WisdomTree DEFA Fund: DWM tracks the WisdomTree Dividend Index of Europe, Far East Asia and Australiasia (DEFA). This is a fundamentally weighted index of nearly 2000 companies. They are in sixteen developed countries in Europe, Singapore, Japan, Australia, New Zealand, and Hong Kong.

DWM is a fund of funds because it primarily invests in the more specific WisdomTree funds. These are the WisdomTree Europe Total Dividend Fund, the Japan Total Dividend Fund, and the Pacific ex-Japan Total Dividend Fund. DWM's net expense ratio is 0.48%. Its distribution yield is 4.59%.

WisdomTree DEFA Equity Income Fund: DTH consists of the companies in the WisdomTree DEFA Index with the highest dividend yields. They must also have a market cap of at least $200 million and average trading volume of at least $200,000 per day for the past three months.

Top countries included in this ETF are currently The United Kingdom, France, Spain, Australia, and Germany. Its top holding is BP (formerly British Petroleum). DTH's expense ratio is 0.58%. Its yield is 2.61%.

WisdomTree Emerging Markets Equity Income Fund: DEM replicates the performance of the WisdomTree Emerging Markets Equity Income Index. This measures the companies in WisdomTree's Emerging Markets Index which pay the highest dividend yields. They have to be in the top 30% of companies in the index. DEM's expense ratio is 0.63%. Its overall dividend yield is 5.32%.

Top emerging countries in this fund are Taiwan, South Africa, Brazil, Isreal, and Malaysia. The top company is the Nan Ya Plastics Corporation of Taiwan.

For the greatest diversification and growth potential investors should consider buying one of the first three ETFS and DEM. That way they can profit from companies in both developed and developing countries.