Speaking of the departure, ACSI said that Ms Byrne had played a significant role in assisting super funds to focus on the environmental and social governance (ESG) factors of their investments.

“Ann’s direct style and her intellectual savvy are well known to many chairs and directors of the stock exchange’s top 200 companies,” ACSI president Gerard Noonan said.

“She has been an articulate advocate on ESG issues for many years and has a deep understanding, on behalf of millions of super fund members, of the importance of improved corporate governance in Australia’s corporate landscape.

“Ann’s drive and enthusiasm has seen ACSI grow into a major force in the corporate governance in Australia as well as assist superannuation funds to focus on the environmental and social impact of companies in which they invest."

Over the last year, Ms Byrne has been focused on a major project to reorganise ACSI’s own governance and representative structure.

She is a former chief executive of UniSuper and Superannuation Trust of Australia (now AustralianSuper).

Ms Byrne has also held the position of elected member of the international board of the United Nations Principle for Responsible Investment (UNPRI) for the past three years and will continue that role until October.

She is also a board member of Oxfam Australia, a member of the Monash University Department of Accounting and Finance Advisory Committee, a member of the BlackRock Australia compliance and national convenor of Sisters in Crime.

ACSI has begun a search for Ms Byrne’s replacement.