The Commerce Commission has filed proceedings in Auckland’s High Court against Winstone Wallboards, a subsidiary of Fletcher Building, for allegedly breaching New Zealand’s Commerce Act through anti-competitive practices. The charges relate to Winstone’s use of retroactive tiered rebates in plasterboard supply agreements with merchants from 2017 to 2022.
Commission Chair John Small highlighted the potential harm posed by these practices, stating that while rebates can sometimes benefit the market, retroactive tiered rebates—especially by a dominant supplier—can limit smaller suppliers’ ability to compete effectively. “In this case, we allege Winstone used retroactive rebates to damage competition, ultimately leading to consumers paying higher prices,” he said.
The Commission’s market study into residential building supplies, completed in December 2022, previously flagged retroactive rebates as a barrier to competition in the sector. Proceedings have been initiated under sections 27 and 36 of the Commerce Act, which prohibit agreements and actions likely to reduce market competition.
The Commission is unable to provide further comment due to ongoing court proceedings.
