The OIO decision last week did not disclose how much the deal was worth.
Daiken was in April cleared by the Commerce Commission to buy the Dongwha MDF (medium-density fibreboard) plant, saying it was satisfied the business merger would not substantially lessen competition in the construction materials supply market.
Korean-owned Dongwha was 80% owned by Dongwha International Co, a Hong Kong incorporated company, and 20% by Laminex Group, a division of listed Fletcher Building.
Fletcher is in the process of selling several non-core assets, after mounting accumulated and expected losses of $952 million from one construction division.
Daiken’s parent company, Daiken Corp, is a Japanese company specialising in the manufacture and supply of wood-based construction materials. Its New Zealand subsidiary produces only MDF.
Laminex had bought MDF from Dongwha for its own New Zealand wood products business and also on-sold some of the MDF to other parties.