3 of 10
3. Merck
Untaxed foreign profit: $40.4 billion

Merck operates in more than 140 countries, delivering prescription medicines, vaccines, biologic therapies, and other pharmaceutical products to consumers and health care facilities around the globe.

While the pharmaceutical giant has kept large sums of its earnings overseas in order to avoid U.S. taxes, it has also found ways to bring some of it back without paying the full tax. According to Bloomberg, Merck brought more than $9 billion from abroad in 2008 without paying any U.S. tax to help finance its acquisition of Schering-Plough. Tax consultants have made a mint advising companies on loopholes to the repatriation tax over the years.

NEXT: Johnson & Johnson
Last updated April 14 2011: 3:59 PM ET
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