MUNCIE, Ind. (AP): Ball State University‘s severance agreement giving the school president a two-month leave ahead of his resignation follows provisions of his contract allowing for him to be terminated without cause with a 60-day notice.

The reasons for President Paul Ferguson’s resignation after less than 18 months remained unclear Tuesday, a day after the university’s Board of Trustees approved his departure plans.

Board Chairman Rick Hall tells The Star Press that Ferguson offered to resign and called the move a mutual decision.

Ferguson’s severance deal gives him a paid, two-month sabbatical leave followed by a year of pay at his base salary of $450,000.

The contract Ferguson signed in 2014 allowed the board to place him on paid sabbatical leave during the 60-day notice period for firing him without cause.