In a surprise development, Vice Adm. John R. Ryan, chancellor of the State University of New York, will announce today that he will resign on May 31, according to the Associated Press.

Admiral Ryan, who was appointed chancellor of the 64-campus system in December 2005, wrote a letter, dated today, to SUNY officials and employees. In it, according to the AP, he said he had “mixed emotions” as he announced that he would be leaving to become president and chief executive of the Center for Creative Leadership, a nonprofit group in Greensboro, N.C.

Admiral Ryan, who led two campuses of the SUNY system as well as the United States Naval Academy before becoming chancellor, had raised hopes among the state’s higher-education leaders that his tenure would mark a defining period in SUNY’s history. Breaking with a recent history of modest budget requests by SUNY leaders, Admiral Ryan had successfully pressed the state to provide more-significant budget increases during his short tenure.

The selection of Admiral Ryan, who does not have an overt allegiance to any political party, also had calmed much of the talk about undue partisan influence at the SUNY system. His predecessor, Robert L. King, had close ties to the governor at the time, George E. Pataki, a Republican. In April 2005, Mr. King announced his resignation after being at the center of several controversies and amid rumors that he had fallen out of favor with the governor and some SUNY leaders.