The president of University of Maine Fort Kent announced his retirement on Tuesday, the latest in a string of top leadership changes at the seven-campus system that has started to affect the system’s bond rating.

The announcement by Wilson Hess means the system has only two permanent presidents, Kate Foster in Farmington and Linda Schott in Presque Isle, both of whom were hired in 2012. The other campuses have temporary presidents, serving terms up to two years.

The University of Southern Maine campus recently hired a new permanent president, Harvey Kesselman, who will begin July 1. Currently Kesselman is acting president of Stockton College in New Jersey, where the president resigned last month after New York financier Donald Trump blocked the school’s plan to open a campus in a shuttered casino on the boardwalk that the university had purchased for $18 million.

The system’s flagship campus in Orono is led by President Sue Hunter, who was named to a two-year temporary term in July 2014. USM, the second-largest campus, has had two temporary presidents over the last three years and is currently led by President David Flanagan; the Augusta campus is led by Glenn Cummings, who was named to an open-ended temporary position in September 2014; and the Machias campus is led by President Joyce Hedlund, who was named to an open-ended temporary position in December 2014.

A temporary replacement for Hess will be in place by early summer, according to system spokesman Dan Demeritt. It is unknown when the system will open a search for a permanent replacement, he said.

In April, credit raing agency Standard & Poor’s downgraded its long-term outlook for the system from stable to negative, citing declining enrollment and high turnover among leadership at the seven campuses. The New York agency left the system’s credit rating unchanged at AA- on outstanding revenue debt, and also assigned a rating of AA- to the system’s $46.24 million in 2015 bonds.

Downgrading the outlook means that S&P thinks the system’s rating could be downgraded to an A+ if declining enrollment and revenue continue. A lower credit rating would mean the system would have to pay higher interest rates on any future borrowing.

Standard & Poor’s credit analyst Ken Rodgers noted the “significant turnover in leadership,” adding “we feel some weakness in governance and management might be occurring.”

On Tuesday, Hess said he was retiring after five years in office, having succeeded in turning around the school’s declining enrollment.

“I leave with a sense of completion,” Hess said in a statement, noting that enrollment grew 24 percent from fall 2010 to fall 2014.

“President Hess has provided his campus and the entire St. John Valley with innovative and strong, community-focused leadership,” Chancellor James Page said in a statement.

“On behalf of the Board of Trustees and our colleagues at each of Maine’s universities, I want to thank Wilson for his many accomplishments, his leadership, and the friendship that will persist long after he leaves office.”