The Commerce Commission says Transpower will be treated differently from other energy network providers when proposed price increases are being considered.
The commission threatened to impose price controls on Transpower in 2006, accusing the national grid operator of breaching set limits on transmission price increases.
In 2008, the two organisations reached a settlement over price rises covering the period to 2011.
The commission now says individual regulation of Transpower is best when considering price increases when the settlement runs out next year.
It says the move reflects Transpower's large and uncertain capital expenditure programme to add to, or upgrade, the backbone of the country's electricity network.