DENVER, SEPT. 26 -- A former federal government attorney who said he pursued dozens of cases involving violations of banking regulations testified today that he has never seen charges as insubstantial as those against Neil Bush.

Charles M. Pickett, formerly in charge of litigation in four states for the Federal Deposit Insurance Fund, testified on a day of dueling experts in an administrative hearing into charges that Bush violated conflict of interest rules as a director of Silverado Banking, Savings and Loan, a failed Denver thrift.

The Office of Thrift Supervision is seeking a "cease and desist" order against Bush prohibiting him from the kinds of activities he engaged in at Silverado.

Pickett and another legal expert for the defense insisted that Bush adequately disclosed his business ties with Kenneth M. Good when Bush sought a $900,000 line of credit for Good and when Silverado released collateral for $8 million in loans to Good.

Both witnesses also said that Bush was not required, as OTS claims, to abstain from votes on loans to Bill L. Walters, another investor in Bush's oil and gas firm.

But Edward J. Conry, a University of Colorado professor presented by OTS as an expert in business ethics, testified that Bush "deceived himself" into thinking he was not compromised by his business interests. The issue of what conflict of interest standard should be used to judge Bush's conduct has yet to be resolved.

Administrative law judge Daniel Davidson has focused his questions and comments partly on whether Bush disclosed he had formed a company called JNB International as part of a partnership with Good that sought to bid on Argentine oil and gas projects. Bush asked Silverado to grant a $900,000 line of credit to Good to show the partnership's financial strength to the Argentine government.

A memo on Bush's request by Silverado's chief lending officer does not specifically mention the partnership with JNB International, although it does state that Good is in business with JNB Exploration Co.