The Commerce Commission says conditions are improving in the telecommunications industry, however a small number of companies still maintain a high market share.
The commission has issued a monitoring report for 2009 and also looked at changes since recent law changes in the industry.
Telecommunications Commissioner Ross Patterson says the results show competition in all telecommunications markets increased between 2006 and 2009. Consumer choice and service quality improved and prices fell.
But Dr Patterson says the market in New Zealand remains concentrated in a few hands - more so than in Britain or Australia - and mobile voice traffic remains low by international standards.
There is also a large price differential when callers phone from one network to a subscriber on a rival company.
Dr Patterson says the New Zealand uptake of broadband has improved from the 22nd spot to the 18th in the OECD - close to the average.