The New Zealand stock exchange has picked a new chairman to take over its board immediately, after the previous pick resigned before he took the seat.

Former stockbroker John McMahon was announced to the top job on Wednesday, one week after being appointed an independent director.

Rob Hamilton was set to become the NZX chairman in April, but he resigned in March when the NZX board withdrew its support for him in the wake of legal proceedings against SkyCity Adelaide in Australia.

A “disappointed” Hamilton was formerly SkyCity’s chief financial officer.

 “The Austrac claim is not against me personally. I am not involved in any way in the claim, nor do I expect to be.” Hamilton said in April.

Rob Hamilton was the initial pick for the NZX chair seat, but the board withdrew their support for him at the last minute. Photo / Greg Bowker

“As a result of Mr Hamilton no longer being the proposed successor to the chair, Mr Hamilton has resigned as an NZX director with immediate effect to help NZX move forward without any distractions relating to this matter,” then-chair James Miller said at the time.

McMahon’s appointment is his second stint at the NZX - he resigned from the board in late 2021 to assume part-time executive responsibilities at the NZX-listed company he chairs, Solution Dynamics, when its chief executive became ill.

He is also chairman of NZX-listed company Vital Healthcare and director of refrigeration technology company AoFrio, formerly named Wellington Drive Technologies.

 “As chair of NZX, I look forward to working with the NZX board, management and investment community in helping strengthen and deepen New Zealand’s capital markets, building on James’ legacy,” McMahon said in a written statement on Wednesday.

“I am a strong supporter of the exchange’s core markets strategy, leveraging value off the business investments that have been made, delivering the Capital Markets 2029 vision and bringing a sharp focus to ensuring NZX is fully focused on shareholder wealth creation.”

McMahon would take on the role immediately, with Miller stepping down.

“James has gone above and beyond in his support of NZX and New Zealand’s capital markets,” his successor said.

“The NZX board and management strongly thank James for his significant contribution to the company and NZ’s capital markets, and wish him all the best for the future.”

McMahon’s career spans more than 20 years in Australasian equity markets, mostly as an equity analyst, working for ABN AMRO, Credit Suisse Boston, BZW, Morgan Stanley, Walker Capital and ASB Securities.

He holds a Bachelor of Commerce with Honours, a Master of Business Administration and is a chartered financial accountant.

He manages his own investment portfolio.