Broadband speeds have improved in New Zealand, but deteriorate the further users are from Auckland, says the Commerce Commission.
The commission analysed broadband speeds in the last three months of 2009 and found that those using the internet in Auckland enjoyed much higher speeds than those in the rest of the country.
It found that, in general, the further the user was from Auckland, the slower the broadband speed. This was because most internet service providers were based in Auckland, as was their key equipment.
For example, in both Hamilton and Dunedin, none of internet companies could provide the minimum benchmark speed, which is 60% of the company's maximum speed available.
The average speed was actually half of the minimum required.
Only two companies in Christchurch met the criteria, and only one company did so in Wellington.
The Telecommunications Users Association says internet service providers should be rated by the commission so customers can gauge how they are performing.
Association chief executive Ernie Newman says the different providers mentioned in the commission's report should have been named.
Mr Newman says concerns about broadband speeds will cease to exist once fibre optic replaces copper.