The announcement was made Monday by university president Franco Vaccarino.
“Martha has been a devoted ambassador for the university, enthusiastically supporting students and working hard to represent the university to government and the public,” Vaccarino said in a statement. “We appreciate her many contributions, both as chancellor and as a proud U of G alumna.”
On April 22, the university’s board of governors voted to move its investments through its endowment portfolio away from fossil fuels over the next five years.
Billes, who voted against the motion, is a controlling shareholder of Canadian Tire Corp. and was named the university’s ninth chancellor in 2017.
“Martha’s relationship with U of G is longstanding and her connection and affection for the university remains strong,” Vaccarino wrote. “We appreciate the many positive things she accomplished during her tenure and wish her all the best.”
The university said the search for a new chancellor will be overseen by its senate and more information will be released soon.
In an email on Monday evening, Billes said she has enjoyed her time as chancellor and remains a passionate champion of the university.
“For over 40 years, I have been an investor in business ventures including the oil businesses in my home city of Calgary and my family business, Canadian Tire Corp.,” Billes wrote.
“My decision to resign as chancellor was prompted by the incompatibility of my business interests with the board of governors’ decision to divest from fossil fuel companies in its endowment portfolio.”