A petty officer at a U.S. Navy training base was ordered demoted to the lowest enlisted grade Saturday after being convicted of sexual harassment and other charges.

The petty officer, Gregg Peterson, 34, was convicted Friday in a special court martial of sexual harassment, fraternization and dereliction of duty for incidents involving alleged harassment of female sailors at the Great Lakes Naval Training Center late last year, said Bill Dermody, assistant public affairs officer at the base.