Westpac Banking Corp has appointed David McLean as chief executive of its New Zealand unit, a position he has held in an acting capacity since August last year.

McLean stepped in to fill the gap left by Westpac New Zealand head Peter Clare, who resigned last year to recover from heart surgery. McLean had been heading up the Americas division of Westpac Institutional Bank before taking on the acting role, and has previously been in charge of Westpac's New Zealand institutional banking division.

"It is important to me that someone with such in-depth knowledge of the business and local market will be taking on this critical role for the group," Westpac group chief executive Brian Hartzer said. "Despite strong competition, David has overseen quality growth of all of the major portfolios of the business and most recently Westpac New Zealand delivered a double digit increase in cash earnings."

The appointment of a New Zealand banking head coincides with the start of Hartzer's tenure as chief executive of the wider Westpac group. Hartzer today changed some of the senior management responsibilities and reporting lines, with heads of retail and business banking, St George Banking Group, BT Financial Group and the bank's technology function reporting directly to him.

The Australian financial services division was disbanded, and its operations will now be the responsibility of Westpac's chief operating officer.

Westpac's dual-listed shares fell 0.4 percent to $36.90 on the NZX.