"When companies merged years ago," says Martin Weinstein of Willkie Farr & Gallagher, "there was a general feeling that organizations came with warts. It's a very new idea that an acquiror can be made to pay for sins that the target committed. And it changes the dynamics of how to do deals." Corruption, it seems, has become a deal-breaker.

For two decades, prosecutions under the U.S. Foreign Corrupt Practices Act of 1977 bumped along at the rate of one or two a year. But in the past year, the U.S. Department of Justice and the Securities and Exchange Commission have brought FCPA actions against (or settled with) six companies.

Suspicions of past corruption in an acquisition target killed a $2 billion deal in 2004-the planned purchase of The Titan Corporation by Lockheed Martin Corporation-and delayed two others on the order of $1 billion: the sale of ABB Ltd.'s energy assets to a private equity partnership, and the purchase of InVision Technologies Inc. by General Electric Company. The past year also saw two of the three steepest fines in the act's history, with Titan paying a record $28.5 million last month.