Mr Brandweiner, who joined First State Super from Perpetual in 2013, will be replaced as CIO of the super fund (in an acting capacity) by StatePlus head Damian Graham.
His decision to join LeapFrog Investments comes after Mr Brandweiner's public endorsement of issues such as impact investing and universal ownership on behalf of First State Super.
The super fund's chief executive, Michael Dwyer, said First State Super has been a "leading advocate for the superannuation industry to play a greater role in developing high quality investments that deliver both financial and social outcomes".
"We are keen to work with Richard and the team at LeapFrog to develop investment vehicles that will deliver on this objective on a global scale whilst generating strong investment returns for our members," Mr Dwyer said.
First State Super chairman Neil Cochrane said Mr Brandweiner has guided the growth of the fund's internal investment capacity throughout the past four years.
"Following our [May 2016] purchase of StatePlus, First State Super now controls one of the largest pools of capital in Australia and this presents new opportunities for growth," Mr Cochrane said.
First State Super is the custodian of a total asset pool of $71 billion, including $50 billion in superannuation and an additional $21 billion in retirement savings.
Read more:
Look past 'market noise', says Vanguard
Equip Super launches robo-advice service
AllianceBernstein hires research analyst
Super funds to face 'uncomfortable' scrutiny
Indian government policy kick-starts growth
