NEW YORK (CNN/Money) - The Chicken Little crowd may see impending disaster in the dollar's drop, but for many U.S. companies it looks more like a windfall.

The greenback has been taking heavy hits lately as currency traders fret that the U.S. economy won't be the draw for the world's cash that it's been in the past.

And steady dollar selling -- it's near a four-year low against the euro -- has sparked worries that foreign investors may decide to pull money out of the United States in a hurry. That wouldn't be pretty.

But the fall in the dollar is money in the bank for U.S. companies doing business overseas, because each sale they make abroad translates into more money at home.

Bang from a banged up buck Nine of the ten companies in the S&P 500 with the heaviest foreign exposure have outperformed this year. Company  Foreign Exposure  2003 stock performance*  Freeport McMoRan  92%  19.6%  Tupperware  85%  -2.4%  nVidia  82%  75.5%  Aflac  80%  6.2%  Comverse  76%  24.8%  National Semiconductor  75%  53.1%  Colgate-Palmolive  72%  13.7%  Texas Instruments  72%  25.1%  Applied Materials  71%  5.6%  Schlumberger  70%  10.5%   *Stock performance through 5/20  Source:  Merrill Lynch and Thomson/Baseline

How much of a boost can the weaker dollar give to company profits?

Plenty. According to Merrill Lynch's strategy group, 25 companies in the S&P 500 get more than 60 percent of their sales from overseas. Top on that list is mining company Freeport-McMoRan, which gets 92 percent of its sales from abroad.

Running further down the list, what you notice is how many of the names are technology related. Chipmaker nVidia pulls about 82 percent of its sales from overseas, Comverse's overseas take is around 76 percent, and Intel pulls down 65 percent.

All told, 12 of the 25 S&P companies with the highest foreign exposure are tech.

The other thing you might notice as you run down the list is how well the stocks of the foreign-exposed companies have done this year. If you'd bought an equal-weighted basket of them at the end of last year, you'd be up some 23 percent now. The S&P 500, in contrast, is up less than 5 percent on the year.

Still, investors need to tread carefully when it comes to figuring out which companies benefit most from a weak dollar, points out Brett Gallagher, head of U.S. equities at Julius Baer Capital Management.

"Some companies have a policy of currency hedging, and you have to factor that into the picture," Gallagher said.

Currency hedging is the use of financial market instruments to minimize the effects of currency swings on profits. As a result, a company like Freeport, which hedges, will not see the weakness in the dollar translate into improved revenues as quickly as nVidia, which doesn't.

Also an issue in trying to determine exposure effects is whether a company sells its products overseas in local currency terms.

Intel, which makes 65 percent of its sales overseas, sells all its chips in dollar terms. That doesn't mean that the weak dollar doesn't help Intel -- over time, it makes its products (or the computers its products go into) cheaper for foreign buyers, which should boost demand. But that's an effect that takes place only over time.

Currency translation effects are the most immediate way that the lower dollar will boost profits, said Morgan Stanley's chief U.S. economist Richard Berner, but not the only one. If the dollar's weakness persists, U.S. companies will be able to better compete with their foreign counterparts both at home and abroad.

In the end, this should bring about an increase in global market share.

That wouldn't be very good for foreign companies -- which, ultimately, could also be a good thing for the world's economy, thinks Berner. A strong yen, for example, would mean that Japanese policy makers would have to throw in the towel on the notion that exports will bail them out, and force them to confront the problems afflicting the economy.

Meantime, the European Central Bank, which has been slow to cut rates despite the weakness of the European economy, might be spurred to action.

"Ultimately, a weaker dollar will spur policy shifts abroad that will be good for global growth," said Berner. "Ultimately, that will help earnings as well."