A jury found Minnesota businessman Tom Petters guilty of 20 counts of fraud, conspiracy and other charges Wednesday in what prosecutors said was a $3.5 billion Ponzi scheme.

Petters, who had claimed that subordinates carried out the scheme without his knowledge, sat glumly as the verdicts were read in federal court. He was convicted of wire fraud, mail fraud, conspiracy and money laundering.

U.S. District Judge Richard Kyle did not immediately set a sentencing date.

Prosecutors had alleged the scheme worked by using fraudulent documents such as purchase orders and bank statements forged by Petters Co. Inc. vice presidents Deanna Coleman and Bob White to trick investors into thinking they were financing purchases of TVs and other electronic goods that would be resold to discount retailers such as Sam's Club, Costco and BJ's Wholesale Club.

The government said two other defendants — Larry Reynolds and Michael Catain — helped launder billions of dollars by allowing PCI to run it through their own businesses' accounts to make it look like their companies were the source of the nonexistent merchandise.

Defense attorney Paul Engh agreed there had been a large fraud at PCI. But he said Petters was an innocent victim of it.

Engh contended that Coleman, White, Reynolds and Catain carried it out behind Petters' back. He said there was ample reason for jurors to distrust them: All four of them reached plea deals, then testified against Petters in hopes of getting lighter sentences.

Two other defendants also pleaded guilty. Sentencing hearings for the six have not been scheduled.

Engh depicted Petters as a visionary entrepreneur and generous philanthropist who did numerous legitimate merchandise deals, but focused most of his attention in recent years on his acquisitions of catalog retailer Fingerhut, Polaroid, and Sun Country Airlines, as well as his charitable work.

Assistant U.S. Attorney John Marti pointed to evidence that showed most of the investors' money went to pay off other investors, but that some $400 million went to PCI, where he said Petters used it to buy Fingerhut, Polaroid and Sun Country or subsidize money-losing companies in his Petters Group Worldwide empire. He said the $400 million total also included $82 million that flowed into Petters' personal accounts, and that Petters used it to "live the life of a corporate tycoon."