William Donaldson, chairman of the U.S. Securities and Exchange Commission, stressed that it was "too early to tell exactly what's going on at Parmalat.

"Clearly there's been a massive fraud," he told a meeting organized by the European Policy Centre, a Brussels-based think-tank.

But he noted that in dissecting the recent scandal at the U.S. energy trader Enron, U.S. authorities concluded there had been "enablement" there by financial institutions.

"We took actions against not just Enron people but against some of their bankers because we felt that the bankers knew exactly what was going on," Donaldson said in response to a question about lessons from the Enron scandal that might apply to the Parmalat probe.

J.P. Morgan, Citigroup and Merrill Lynch paid $135 million, $101 million and $80 million respectively to settle charges over their role in Enron's fraud, without admitting or denying wrongdoing.

Meanwhile, a new audit of Parmalat found that the dairy conglomerate's net debt was about $15.6 billion more than what it reported in the fall, months before the huge fraud scandal erupted, the company said Monday.

The audit, ordered by Parmalat's court-appointed administrator to discover what the true books really showed, found that according to company accounts, net debt for the nine-month period ending Sept. 30 stood at $17.9 billion, and not at the $2.25 billion that Parmalat reported back then.

The latest debt figure was largely in line with estimates cited by economic observers in the early weeks of the scandal and some investigators.

The scandal exploded in December after the company admitted that it did not have a nearly $5 billion Bank of America account as Parmalat had stated in September. Bank of America has said that the letter testifying to the account was a forgery.

Soon after, Parmalat went into bankruptcy protection.

Investigators have been scrutinizing Parmalat records and employees and checking the documentation of banks that placed Parmalat bonds or gave it credit. The Bank of Italy also handed over documents to Italian police Saturday.

The SEC filed a civil lawsuit against Parmalat last month. It also is examining the role of big investment banks in helping the company sell bonds and questioning whether they turned a blind eye to irregularities in company books.

"We've had our dose of malfeasance ... and we've had now some similar things on this side of the ocean," he said, citing not only Parmalat but other European companies that have run into accounting trouble, including Royal Ahold in the Netherlands and Swiss-based Adecco.

"It's made us all realize that fraud knows no boundaries," he said. "The lesson from Parmalat is the lesson of the need for cooperation," adding that so far the SEC has had "great cooperation, particularly on the Parmalat case" with Italy.

-- Paul Geitner, AP Business Writer