The body representing most of the infant formula industry is seeking approval from the Commerce Commission for its rules restricting advertising of formula.
Under New Zealand law, it is illegal to be anti-competitive.
However, the Infant Nutrition Council, which represents 95 percent of manufacturers, marketers and importers of infant formula in New Zealand, has a voluntary code of conduct which includes not advertising infant formula.
Chief executive Jan Carey said the agreement was in place to ensure that breast-feeding is not undermined and the council was going to the commission to formalise this.
"We've been doing that for many years - it's a self-regulation code of practice that we don't advertise our infant formula products to the general public because we want to protect breast feeding. We don't want people to think infant formula is better or as good as breast feeding."
Ms Carey said other restrictions include not distributing gifts or free samples to pregnant mothers and not offering incentives to health professionals to promote infant formula.
The Commerce Commission said if the public benefits of the agreement outweigh the loss from the lack of competition, authorisation may be granted.
