Sheffield Consulting's Garry Diack has warned New Zealand that it is "dangerous" to channel a quarter of its export economy through one company.

Diack, dubbed a "governance guru" by the Gold Coast Bulletin, denounced the reforms to the country's dairy industry that enabled the creation of the Fonterra Co-operative Group, the fourth-largest dairy company in the world.

The dairy industry accounted for between 21% and 23% of NZ's export revenue in the 1999-00 period, and 98% of that revenue was driven by Fonterra, which itself accounts for 7% of NZ's gross domestic product.

Fonterra's 2002 revenue is forecast at NZ$14bn (US$5.78bn).