Gas consumers look set to get an average 6 percent cut in the price of their monthly bill for the 2017/8 year.
This follows a decision by the Commerce Commission, which regulates gas pipelines as natural monopolies.
It does this by determining how much money the companies can make.
After lengthy debate, it has issued a final determination that this income should fall by 13 percent, or $33 million, a year.
Distribution costs are only part of the total cost of supply gas, so customers will get about half of this benefit, and the 6 percent average cut will vary across different regions.
The companies affected are First Gas Limited, GasNet Limited, Powerco and Vector.