If you've followed international stocks over the past few years, you've surely noticed a trend: foreign companies delisting their stocks from major U.S. exchanges.

In fact, well-known foreign companies such as British Airways, Fiat, and Bayer either announced or implemented their departure from the NYSE last year.

And we can expect this flight from New York to continue.

It's nothing personal; it's just business
Why, you ask? Put simply, the extra costs of following Sarbanes-Oxley (SOX) and various exchange regulations, as well as anemic trading volumes on U.S. exchanges, often outweigh the benefits for these companies.

While some larger companies have also packed their bags, you're unlikely to see large foreign firms with high daily trading volume -- think Research In Motion (Nasdaq: RIMM) and Vodafone (NYSE: VOD) -- leaving Wall Street anytime soon. In these cases, it's more cost effective (and better for public relations) to be listed in the States.

The good news is that you still have access to foreign companies that have delisted their shares: You can pick them up via the Pink Sheets.

Oh, the humanity!
While the Fool typically discourages investors from patrolling the Pink Sheets, using them to purchase quality foreign shares is an exception. Trading guidelines for these over-the-counter shares (place only limit orders, etc.), however, should still be followed.

Even though following SOX and U.S. exchange regulations can be costly for companies, it's important to note that these regulations were largely designed to protect shareholder interests by requiring greater disclosure and adherence to U.S. GAAP. As such, it can be much more difficult to interpret financial statements and estimate a valuation for firms not listed on a U.S. exchange.

To further help you separate the wheat from the chaff, each week we'll take a look at two top-rated foreign companies trading on the Pink Sheets, as rated by the more than 82,000 investors participating in Motley Fool CAPS, the Fool's free investing community.

Como se dice "low prices"?
As the largest retailer in Mexico, Wal-Mart de Mexico (WMMVY.PK) has plenty of room to expand in a growing economy. The region also seems to be more accepting of Wal-Mart's (NYSE: WMT) brand and operating methods, so this probably won't be a repeat of Wal-Mart's failed and expensive attempt to penetrate the German market.

Granted, the fact that WalMex is a Motley Fool Global Gains pick might have something to do with its five-star rating on CAPS, but considering that The Economist thinks Mexico's GDP will grow faster in 2008 and 2009 than it did in 2007, WalMex is indeed a worthy candidate for further research.

CAPS player Kristm seconds that opinion, "Wal-Mart and Mexico are a perfect fit. A conservative company providing low-priced goods and a consistent experience ... a conservative culture, and no other major consistent retailers."

On the other hand, because of close trade relations between the U.S. and Mexico, the Mexican economy tends to have a high correlation to the U.S. economy. If the U.S. economy slumps over in the next few years, it might also harm Mexican growth.

The redcoats are here!
In 2006, British megaretailer Tesco plc (TSCDY.PK) announced that it was expanding its $65 billion business to the U.S. markets, putting it in direct competition with Wal-Mart and Target (NYSE: TGT), as well as grocery stores such as Kroger (NYSE: KR).

Now, it's finally arrived, with 28 "Fresh & Easy" stores sprinkled across southern California, Las Vegas, and Phoenix. Tesco called early customer response "very encouraging."

CAPS player PayItBackward has firsthand experience with the newly opened stores: "Their Fresh & Easy market just opened near me -- it's a winner. These are going to be HUGE."

Tesco CEO Terry Leahy has led the company since 1997 and is surrounded by a seasoned management team that understands Tesco's business and expansion opportunities. Under Leahy's leadership, Tesco shares have risen 150% on the London Stock Exchange. As further testament to management's confidence, Tesco raised its 2007 interim dividend by 13.9%; the stock currently yields 2.4%.

Your turn
What do you think about WalMex, Tesco, or any stock for that matter? Make your voice heard on Motley Fool CAPS today. It's 100% free.

Fool contributor Todd Wenning is ranked 905 out of more than 82,000 investors participating in CAPS. He does not own shares of any company mentioned. Wal-Mart de Mexico is a Global Gains pick. Wal-Mart is a Motley Fool Inside Value choice. The Fool's disclosure policy is always rated five-star.