As tax shelters became the subject of increasing scrutiny, finding out who bought them became equally interesting to the IRS and the media. Newly disclosed KPMG documents show a client list of 29 prominent American business.

Companies such as Delta Air Lines, Whirlpool Corp., Clear Channel Communications Inc., WorldCom Inc., Tenet Healthcare Corp. and the U.S. units of AstraZeneca PLC and Fresenius Medical Care AG made use of a KPMG shelter known as CLAS or name "contested liability acceleration strategy."

Using an aggressive marketing strategy, KPMG helped 29 companies shave $1.7 billion in tax liability, the Wall Street Journal reported.

The KPMG documents show that Qwest Communications International Inc., Washington Mutual Inc., Global Crossing Ltd., Lennar Corp. and the U.S. units of Cemex SA and Siemens AG signed agreements to buy the shelter, but those companies wouldn't say whether they implemented it, the Journal reported.

The IRS declared the tax shelter to be abusive in November 2003, after the 29 companies had bought it from KPMG. Still, "no one purchases a shelter like this without knowing they're taking significant risks," said Joseph Bankman, a tax-law professor at Stanford University. "It's a classic case of getting something for nothing."

In a usual sales scenario, KPMG salespeople would pitch the product to a company’s chief financial officer or vice president for tax, the Journal reported. A January 2000 KPMG slide presentation called CLAS "an aggressive strategy" and told tax partners and managers to target companies that had "implemented risky strategies in the past," the Journal reported.

If a prospective client objected on the grounds that "it's too good to be true," salespeople were advised to respond: "Three elements are involved in any tax strategy: Legislation, regulation and court interpretation. Looking at the legislation alone it is to [sic] good to be true. However, legislation, regulation and court interpretation combined allow the strategy to work. KPMG's advantage: We were involved in drafting the regulations and are acutely aware of the opportunity."