Current Quadrant chief executive Wayne Davy will head up the merged entity from November, at which point Mr Cassidy will officially leave after 24 years' service with Tasplan.
The two industry funds confirmed on 14 November 2014 that they will operate as one entity from November 2015 under the Tasplan brand.
Tasplan chair Naomi Edwards said Mr Cassidy was instrumental in the 1987 creation of Tasplan when he was seconded from National Mutual under a two-year agreement to set up the fund.
“Neil then returned to the organisation in 1998 when he was appointed chief executive officer and has helped make Tasplan Super the leading industry super fund in Tasmania,” Ms Edwards said.
“Neil has always been passionate about working for the best interests of Tasplan members and I know members will join with me in wishing him all the best."
Mr Cassidy hinted at some future roles, saying he was “excited about pursuing new opportunities”.
“I’ve enjoyed my time with Tasplan and with over 40 years’ experience in the industry, I still have a lot to give; so I am looking forward to what the future holds,” he said.
“I wish Tasplan all the best for the future and I know it will be in safe hands."