One of Prof Gillespie’s last public appearances in the role was delivering the vote of thanks to Sue Black, Baroness Black of Strome, following her Margaret Harris Lecture at the university last Friday.
In an all-staff email last month, Prof Iain Gillespie said the university was planning for “a significant deficit” in the wake of “an extremely challenging period” for the UK higher education sector.
He said that despite a recruitment freeze and reducing operational expenditure, the university was still looking at a deficit of between £25m and £30m next year.
He added: “This will be a very difficult period, certainly for this financial year and next.”
In an email to staff confirming Prof Gillespie’s resignation, the university’s chair of court Amanda Millar said the institution was “facing significant challenges to our financial sustainability.”
Ms Millar added: “The university leadership group has been working intensively over recent weeks to develop a recovery plan to address this situation.
“Prof Shane O’Neill, as deputy vice-chancellor and provost, will take on the leadership of the University Executive Group.
“I am optimistic that they, working closely with our court, will re-establish a more stable financial foundation to allow the university to flourish again.”