The Insurance Council says premiums will not be affected by a new licensing regime that has cut the number of insurers by almost a third.
Fifty of the country's 160 insurers failed to meet a deadline last week to obtain a licence to continue in business.
The licence, from the Reserve Bank, is given only to insurers who hold millions of dollars of capital to meet claims.
The Insurance Brokers Association says the rules have weeded out smaller, potentially riskier operators.
But actuary Jonathan Eriksen says that's left larger mainly foreign-owned insurers in a more dominant position.
Insurance Council chief executive Chris Ryan says that, despite the reduction in the number of companies, competition is still strong among the remaining insurers.
He says although this means premiums will not rise due to a lack of competition, they are already increasing as a result of the Christchurch earthquake.