Loudoun County Sheriff Donald L. Lacy will appeal his March 26 conviction on an assault charge in a case growing out of a New Year's Eve incident in a motel lounge near Dulles International Airport, the sheriff said yesterday.

Lacy was found guilty by Fauquier County General District Court Judge John Alexander and fined $100. The 34-year-old sheriff was acquitted of a lesser charge in connection with the incident.

Lacy, who declined to comment further on the case, said his lawyer, Louis Koutoulakos of Arlington, filed a notice of appeal shortly after the misdemeanor assault conviction. The appeal will be heard by a seven-member circuit court jury, he said.

Lacy's role in the incident, which involved a dispute with two young women who were photographing him on the dance floor, was sharply criticized in February by a special grand jury investigating allegations of abuse of power in the Loudoun sheriff's office.

The incident was "an entirely uncalled for scene due to the sheriff's intoxication and poor judgment," the grand jury said, adding that Lacy had "made a fool of himself" there on numerous other occasions.

Lacy denied any wrongdoing. "I have always conducted myself as a gentleman and know my friends will attest to this," Lacy said in a statement issued in response to the grand jury report