Wellington, June 5 NZPA - Kiwibank chief executive Sam Knowles will fill in as New Zealand Post Group chief executive but is not seeking the role permanently.

NZ Post chief executive John Allen is leaving to become secretary of Foreign Affairs and Trade. It was announced today that the group's chief financial officer Peter Schuyt is also leaving at the end of August.

NZ Post chairman Jim Bolger said Mr Knowles will be acting chief executive from July 1. The board expects to make a permanent appointment by September.

"I am delighted that Sam has agreed to step into the role in an acting capacity while recruitment is undertaken," he said.

"Sam has informed the board that he will not be applying for the group chief executive role."

Paul Brock, currently Kiwibank general manager savings and transactions, will take up the role of acting chief executive at Kiwibank until Mr Knowles returns. Kiwibank is a subsidiary of NZ Post.

Mr Bolger said that Mr Schuyt was involved in an increasing portfolio of governance roles outside of the group.

"This regrettably means that Peter will be formally leaving his role at the end of August," Mr Bolger said.

He had made an excellent contribution to the group.