Duncan was warned of possible discipline for shoddy work, executive says.(Chicago Tribune)

HOUSTON _ Three days before Andersen auditor David Duncan began a massive campaign to shred Enron Corp. documents, partners at his firm told Duncan he could be disciplined for shoddy accounting practices on the Enron account, a high-ranking Andersen executive testified Friday at the firm's obstruction of justice trial.

Andersen's defense lawyer, Rusty Hardin, brought out this revelation as part of an effort to demonstrate that Duncan, when he destroyed the documents, intended to protect himself rather than to aid any scheme at Andersen to avoid liability for its audits of Enron.

Andersen is charged with obstruction of justice for allegedly conspiring to …