The Commerce Commission has appointed a new Grocery Commissioner to referee New Zealand's supermarkets.

Former Sanitarium New Zealand boss Pierre van Heerden will take up the role this Thursday.

Commission chair John Small says van Heerden brings more than 25 years of experience on the supply side of the grocery sector.

The appointment is part of reforms brought in by the passing of the Grocery Industry Competition Bill late last month.

It aims to improve fairness and efficiency in the industry, which is largely dominated by Foodstuffs and Woolworths.

Pierre van Heerden joined the Mike Hosking Breakfast.

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