The president of the Muhammad Ali Center in Louisville is stepping down.Greg Roberts took the job in 2008. He plans to leave the center at the end of June to pursue a career in education and public policy. The center will begin searching for a successor immediately. Board chair Shirley Willihnganz says the new president should have some of the skills and qualities Roberts has."I think he's done an incredible job of networking and connecting the center and the community," she says. "He's certainly taken care of a lot of issues in the building, things that needed repair and update and needed to be fixed up. I think he's done a good job of connecting us to donors and funding agencies."Willihnganz says the board had a cordial relationship with Roberts. However, she says like every nonprofit in the current economy, the center had its share of financial frustrations. She says that was not the reason behind Robert's departure.The center recently reached a fundraising goal of $4 million toward its Legacy Campaign, and officials hope to raise an additional $6 million in the next three years. According to a statement, Roberts departure is not expected to affect the campaign.