Financial Markets Authority chief executive Rob Everett is leaving the organisation after seven years.
He has been with the FMA since February 2014 and has overseen a broad expansion of its regulatory powers throughout the financial sector.
FMA chair Mark Todd said Everett had done an outstanding job in implementing the Financial Markets Conduct Act and promoting the discussion about regulating conduct in financial services.
"Rob has been, and will continue to be, a truly outstanding leader of the FMA, who will leave a lasting legacy. He has the greatest respect both within the FMA and among our many stakeholders," Todd said.
"Looking ahead, the FMA's regulatory remit is expanding with the implementation of financial adviser reforms and the introduction of new legislation to provide for the regulation of conduct for banks and insurers. The timing of Rob's departure creates an opportunity for the next CE (chief executive) to advance this work," Todd said.
A tentative leaving date of 30 September has been agreed on.
Everett said he had enjoyed his time at the FMA and was proud that the organisation was seen as a high performing organisation that punched above its weight.
"My focus is to support the board and ensure we don't drop any balls in the months ahead. I intend to take a good break over the summer to consider my next move."