The merger of the Aon and Equity Trustees super funds will create a $5.2 billion fund after APRA gives it the nod.
Under the agreement to merge the Aon Master Trust and the Executive Superannuation Fund, Equity Trustees will assume responsibility for the trustee services and Aon will look after products and distribution.
Equity Trustees managing director Mick O'Brien said the fund merger is consistent with his firm's core fiduciary responsibility.
"With $130 billion in funds under management globally, Aon brings international expertise to superannuation solutions at a time when the industry is increasingly moving to a global outlook," Mr O'Brien said.
Aon Hewitt Pacific chief executive Steven Gaffney said, "Equity Trustees brings its specialist independent trustee skills to an industry that is growing, and increasingly dependent on capable and trustworthy oversight.
"The relationship with Equity Trustees means we can empower our members and provide access to a broader range of products and services to secure a better future for themselves.
"The increased breadth and depth of the fund means we will be positioned to offer even greater advantages for our members, including lower costs and increased buying power to provide superior investment options."