MTAA Super chief executive Michael Delaney has resigned from his position and will step down in early November this year.
The fund has not yet found a successor for Delaney, who was the founding chief executive of the fund and has been at the helm since 1989.
The resignation comes after Delaney had received a vote of no confidence by its shareholders, while the $5.8 industry fund was under investigation by the Australian Prudential Regulatory Authority (APRA) for investment losses in 2008, after the fund decided to be temporarily unhedged.
"The trustee has put in place appropriate processes to ensure a new CEO will be considered, appointed and in place by later this year," the fund said on Friday.
MTAA Super will also restructure its board and change its composition of four employer nominated representatives, four member nominated representatives and one independent chair to a composition of three employer nominated representatives, three member nominated representatives and three independent directors.
"This change has the support of the prudential regulator, APRA," the fund said.
Employer nominated directors Bob Allen and member nominated director Mark Perica will retire at the end of their current appointment terms in November, and the fund has engaged a recruitment firm to start a search process.
APRA did not confirm whether these measures concluded the investigation into MTAA Super.
A spokesperson said APRA could not comment on the regulator's dealings with specific institutions.
"The decisions announced today represent a new era for MTAA Super," MTAA Super chairman John Brumby said.
"The changes will not only broaden and strengthen the board of directors, but renew and refresh the management of the fund and position the fund as a leader in financial accountability and transparency. Further, the changes bring to an end the issues long disputed by the Motor Trades Association of Australia, which is a welcome outcome for members of the fund," Brumby said.
The changes announced on Friday do not affect the current relationship of the fund with its asset consultant, Access Capital Advisers.
"We have worked closely with chairman John Brumby and we don't expect any changes," Access Capital chief executive Alexander Austin told InvestorDaily.