NEW YORK (CNN/Money) - Arthur Andersen LLP got its wish for a speedy trial Wednesday when the accounting firm pleaded not guilty to a single criminal charge stemming from Andersen's destruction of Enron Corp. documents.

The case is now set to begin May 6 when jury selection is to begin. Federal Judge Melinda Harmon, who will preside over the trial, agreed to change the date from May 20. Harmon is also the judge overseeing the Enron civil and class action lawsuits in Houston.

Earlier Wednesday, U.S. Magistrate Calvin Botley had selected a May 20 date and appointed Harmon as the trial judge. But in a second hearing before Harmon, Andersen attorney Rusty Hardin asked for an earlier date as part of the firm's strategy for a speedy trial. Chicago-based Andersen wants a trial on the indictment to begin within 70 days.

Outside the Houston courtroom, a crowd of Andersen employees protested the criminal charges against the firm and were wearing T-shirts saying "I am Andersen."

The Justice Department indicted Andersen last week for obstruction of justice, related to the firm's shredding of the bankrupt energy trader's documents. In its indictment, Justice alleged that the accounting firm engaged in the wholesale destruction of documents, shredding literally "tons" of papers and purging volumes of information.

On Oct. 23, Andersen began shredding documents even though it found out four days earlier about a Securities and Exchange Commission probe into Enron, the government said.

However, federal prosecutors did not name or charge any individuals or Andersen partners in its indictment.

Attorney Rusty Hardin said Wednesday that Andersen had wanted to set up a fund to compensate Enron employees but the indictment now "knocks that out." Andersen refused to plead guilty last week.

"The reason there is no plea from [Andersen] is that the company didn't commit a crime," Hardin said.

In the first hearing, Judge Botley said the trial could last as little as 25 days. The maximum sentence on the criminal charge against Andersen is $500,000 and five years' probation, Botley said.

Separately, the Securities and Exchange Commission sought a $500 million payment from Arthur Andersen to settle shareholder claims against Enron's former accountant, but the firm offered only $375 million before talks broke down, according to published reports Wednesday.

Andersen originally offered a $750 million payment to settle claims from shareholders, unsecured creditors and employees. The reduced offer is said to be an indication of Andersen's high-profile client defections and the possibility that its overseas offices may be sold to KPMG.

The original offer comprised $250 million in insurance payments and $100 million a year from Andersen's revenue for five years.

"[The new offer] simply reflects their recognition that they can only deliver on the first year's installment," Trey Davis, spokesman for the University of California Board of Regents, told the Wall Street Journal. The board is the lead plaintiff in a class action suit against Andersen filed by Enron shareholders.

Andersen's client defections include Delta Air Lines (DAL: Research, Estimates), package deliverer FedEx Corp. (FDX: Research, Estimates), drugmakers Merck & Co. (MRK: Research, Estimates) and Wyeth Corp. (WYE: Research, Estimates), mortgage financer Freddie Mac (FRE: Research, Estimates) and Dynegy Inc. (DYN: Research, Estimates), the rival energy trader that tried to buy Enron before its collapse.

The SEC's demand for a $500 million settlement reportedly broke down after the company was indicted for obstruction of justice, according to the New York Times.

The breakdown in talks may signal the different paths taken by the SEC and the Department of Justice in seeking a remedy for Andersen's role in Enron's collapse.

The SEC intended to use the $500 million to pay restitution to shareholders who lost assets as Enron crumbled and to recreate Andersen under terms determined by a committee led by former Federal Reserve Chairman Paul Volcker, the Times reported.