The Electricity Authority is reviewing provisions for calling an undesirable trading situation (UTS), which allows the regulator to reset wholesale power prices.
Electricity market participants have been divided over the authority's decision to lower prices from $20,000 to $3000 a megawatt hour in late March, after it deemed the higher prices undesirable and a threat to the integrity of the market.
Genesis Energy, Contact Energy and Todd Energy have challenged that decision.
The authority says it has called for a review to consider differences between the provisions under electricity market rules and those in the code, in particular relating to the test for when an undesirable trading situation has occurred.
The regulator says it may propose amendments to the industry code later this year.