New Zealand's Commerce Commission confirmed a series of targeted updates to the country's fiber settings, according to a Tuesday statement from the regulator.

A key change will be a new investment test for major fiber expansion projects, which will assess proposals using an assessment framework, focused on the consumer benefits of further fiber roll-out while still promoting competition, Telecommunications Commissioner Tristan Gilbertson said.

It also streamlined the process for assessing capital expenditure proposals through clearer information requirements as well as more predictable timelines, and made changes in areas such as connection costs and insurance.

Telecom infrastructure company Chorus' (NZE:CNU, ASX:CNU) Australian and New Zealand shares were each down by about 2% in recent Tuesday trade.