Robert Skalla of Janesville is charged with third-degree sexual assault. He's been released on a signature bond.
The 39-year-old instructor is accused of indecently touching an 18-year-old Blackhawk Tech student March 6 at a Madison hotel.
He was the adviser to a team of students who were attending a conference of the Wisconsin Marketing and Management Association.
Brian Gohlke is the school's director of human resources.
He says the college conducted an investigation after it received a complaint from the student, but it took no disciplinary action because Skalla had resigned.
Skalla had taught there for four years.