The Office of the Bar Counsel yesterday issued its lightest sanction, an informal admonition, to D.C. Council member Adrian M. Fenty for his failure to guard the assets of an elderly man he was assigned to protect six years ago.

Fenty's conduct in the case "reflected a disregard of certain ethical standards," Wallace Eugene Shipp Jr. wrote in a four-page letter delivered to Fenty's attorney. "In sum, the record reveals that you either were not aware of, or did not comply with, several rules and laws governing guardianship and conservatorship, and your actions fell below acceptable standards."

Although Fenty violated rules related to competence, diligence and respect for the administration of justice, Shipp wrote that his office settled on an informal admonition in part because Fenty had no prior disciplinary record, acknowledged his responsibility in the case and "cooperated fully" with the bar counsel's investigation. Fenty also repaid the estate of his ward, William Hardy Sr., "so that the ward was not harmed," Shipp wrote.

In the District, a violation of the rules of professional conduct can carry penalties ranging up to disbarment.

Fenty (D-Ward 4) said he will not challenge Shipp's ruling. His acceptance brings to a close a matter that had cast a shadow over his record as he enters the hotly contested 2006 race for mayor.

"I'm not going to make excuses," Fenty said. "It shouldn't have happened. It won't happen again. But it did happen, and when you make mistakes, you have to be willing to accept responsibility. . . .

"This puts this matter behind me. It's the lowest sanction they can give. It means there's no formal action taken against my license."

Fenty, 34, has not practiced law since he won election to the council in 2000 on a pledge to abandon all outside employment. Hardy's case was among the last he handled before his inauguration in January 2001.

The case dates to 1999, when Fenty was working as a clerk for the council's Education Committee, planning his first council race and accepting court appointments as a newly licensed attorney. That April, a judge appointed him to serve as guardian to Hardy, 88, a retired Navy worker who was allegedly being swindled by his granddaughter, court documents show.

Fenty neglected the case from the start, Shipp found. He failed to immediately inventory Hardy's assets. He submitted only one report detailing Hardy's condition and assets, although he was required to do so every six months. And when Fenty asked to be released from the case in 2000, he "failed to file an accounting . . . revealing the whereabouts of the ward's assets, as ordered by the Court."

When a new guardian, Kimberly Edley, took over, she asked the judge to appoint a special master to investigate Fenty's conduct, court records show. In 2001, the special master determined that more than $22,000 had disappeared from Hardy's bank account on Fenty's watch.

A judge later ordered Fenty to reimburse $15,000 to Hardy's estate, saying Fenty "made a series of errors that lead to both the improper withdrawal of funds by Mr. Hardy's family."

Fenty said that he paid $10,000 and that his attorneys recovered $5,000. An additional $7,000 was later determined to have been spent for Hardy's benefit.

Shipp declined to discuss the case, saying his findings were not yet public because Fenty had yet to formally accept the penalty. In general, an informal admonition is the bar counsel's "quietest form of yelling," Shipp said. "Basically, the subtext is, 'This didn't warrant us prosecuting you, but we expect you to do better in the future.' "

Hardy died in April, shortly after his 94th birthday. Edley, who was still serving as his legal guardian, would not comment on the bar counsel's decision.