But some of the shareholder attorneys suing Andersen and Enron's leadership asserted that a report filed by Andersen on its progress retrieving files destroyed by its Houston staff fails to make clear what files have been trashed and whether they're gone for good.

"The problem with it is it doesn't tell us what documents were destroyed and whether or not they've been able to reconstruct or recover those destroyed documents," said Chris Patti, university counsel for the University of California Board of Regents, which lost about $145 million when Enron collapsed. "There's a lot of technical detail in the report, but it's not ultimately very enlightening on the key issues."

For instance, the report filed to U.S. District Judge Melinda Harmon, who is expected to name a lead plaintiff in the shareholder case as early as Friday, stated that Andersen has collected "roughly 250 terabytes of electronic data." A footnote explains: "By comparison, the entire U.S. Library of Congress is estimated to represent between 20 and 100 terabytes of data. "A terabyte is a trillion bytes."

Of such detail, Patti said, "We don't know whether those are the documents we're concerned with or not."

Plaintiffs hope to answer such questions next week, when they will take depositions from key Andersen officials, including David Duncan, Andersen's fired lead partner in charge of its Enron account, and Nancy Temple, who authored an Oct. 12 email regarding destruction of documents.

Judge Harmon had ordered the report from Andersen on Jan. 23 -- nearly three weeks after Andersen advised the Securities and Exchange Commission and the Justice Department that "an undetermined number of hard copy documents and emails potentially related to Enron had been destroyed or deleted." The SEC had opened a probe of Andersen's Enron audits last fall.

Shareholders' concerns about such document destruction only increased on the eve of the Jan. 23 hearing when a recently laid-off Enron executive revealed that paper shredding continued at Enron as recently as mid-January.

In its report to the court, attorneys for Andersen said it had so far assembled about 4,800 "official work paper files and reports" from 1997 through 2001 as well as "additional work papers and reports dating as far back as 1932."

Andersen also reported collecting about 1,500 boxes of desk files consisting of 3 million sheets of paper from about 235 individuals. And it said it had assembled 4,000 "server backup tapes," 340 personal computers, "100 gigabytes of Connected Network Backup data," at least 50 Palm Pilots, and more than 300 floppy disks and CD-ROMs.

The main storage facility for the material, in downtown Houston, has an armed guard outside 24 hours a day, seven days a week, Andersen said.

"The process we've been going through is to procure documents throughout our system," said Andersen spokesman Charlie Leonard. "We've been trying to determine the volumes and places and sources of information. We've not yet completed the investigation, not yet fully identified all the materials."

Leonard added: "We continue to believe, with respect to e-mail, that all or virtually all will be recovered."

Andersen has hired an outside computer firm, ASR Data Acquisition & Analysis of Cedar Park, Texas, to assist in the recovery of the destroyed records. Andrew S. Rosen, CEO of ASR Data, declined to comment in detail on Thursday.

When asked if Andersen had good reason to think that the bulk of the lost electronic data would be recovered, Rosen replied: "Their optimism is well placed."

Rosen has worked in the past for government agencies retrieving lost electronic files. He is employing specially designed software to help Andersen "create the kind of copy that the legal system requires" by recovering and analyzing lost data.

-- By Flynn McRoberts and Delroy Alexander