CAMBRIDGE, Mass. (AP) _ Harvard University's Kennedy School of Government has issued new rules putting strict limits on how much instructors can become involved with student-launched businesses, the Boston Globe reported.

The school's image could suffer if professors became entangled in students' finances, said Kennedy School dean Joseph Nye.

``If one student in class gets an A, and one gets a B, if student A is in a position to make the professor a lot of money, compared to student B ... you can see how over time, it could have a corrupting effect on the morale of the student body,'' Nye said.

Under the guidelines issued last week, instructors or professors may not advise, invest in or consult for student enterprises until three months after the students graduate.

That is stricter than rules implemented at Harvard's business school, where professors must stay at arm's length from student enterprises only until graduation day.

Gilberto Carrasquero, 36, is partly responsible for the new Kennedy School policy. He attempted unsuccessfully to enlist Nye as an adviser to a business he is developing, govXchange.com.

The rules come at a time when lines between academia and business are blurring. Many schools, among them Harvard and Northeastern, promote student entrepreneurship and license student research.