The Financial Markets Authority is investigating 16 finance companies that involve an estimated $3.45 billion in total of losses to investors.
The authority will make decisions on the most advanced of those cases by the end of this year, including South Canterbury Finance, Hanover and Strategic Finance.
Chief executive Sean Hughes says he wants to restore investors' confidence in the market.
The authority took over work carried out by the Securities Commission and the Ministry of Economic Development four months ago.
It is dropping investigations into six collapsed finance companies because it has not found any evidence yet of anything illegal.
Geneva, Mascot, Strata and All Purpose Finance, along with Direct Property Investments (No 6) and Finance & Leasing owe investors about $40 million.