Tasplan chair Naomi Edwards will head up the new fund created when the merger with MTAA Super completes in October of 2020.
The new fund will have $23 billion funds under management and will represent 335,000 members.
"We are committed to retaining all the personal customer service benefits of a smaller fund, while delivering the financial assurance of a larger one," Ms Edwards said.
"Together our increased scale will deliver stronger investment returns and decreased fees for members as well as delivering improvements and efficiencies in product and service delivery."
Current MTAA Super CEO Leeanne Turner will become CEO of the merged organisation. Tasplan's CEO John Brumby has announced that he will retire.