"I'll still be associated in some shape and form."
Current chairman Neil Craig will temporarily step into the CEO role while the company searches for a new chief executive.
While Sir Ralph Norris will become independent chairman of the board and will also be joined by Susan Peterson as an independent director.
"We have been looking for two independent directors. We started that process in August/September last year.
"I just feel the timing is right with two independents coming on board and me doing 16 years, it's time to just have a refresh of the board structure, management team and for me just to get a bit of a break."
Aldridge said there was no set date for his departure but it would be soon.
"I want the board to have a clean mandate to do that process and hire someone else. It is better I just take a step back and do a bit of ticky touring."
Last year Craigs Investment Partners formed a strategic alliance with JP Morgan to help fill a void left after Deutsche Bank sold its 49.9 per cent stake in Craigs in 2019.
Craigs also owns a 50 per cent stake in Australia investment firm Wilsons.