The chairman of the University of Massachusetts system’s governing board said yesterday he would step down at the end of the year, according to The Boston Globe.

The state’s governor, Deval L. Patrick, a Democrat, has twice tried to oust Stephen P. Tocco, a former state official, who was appointed to the board by Mr. Patrick’s predecessor, Mitt Romney, now a candidate for the Republican presidential nomination.

Mr. Tocco, who will remain on the board, will reportedly be replaced by Robert J. Manning, its vice chairman. In a letter sent to fellow board members last night, Mr. Tocco said: “The ongoing discussion and related anxiety over the chairman question has been a distraction long enough.”

The board shake-up follows other recent signs of turbulence at the five-campus system. Most notably, a leadership tussle at the Amherst campus was followed by the July departure of John V. Lombardi, the outspoken chancellor at Amherst, who left to become president of the Louisiana State University system. —Paul Fain