State regulators Monday approved third-quarter health insurance rates that will raise premiums an average of just 1.2 percent in the market serving small businesses and individuals, continuing a trend of more modest increases seen over the past three quarters.

The new rates are in the Massachusetts “small group” market, which includes tens of thousands of small companies as well as self-employed and formerly uninsured individuals. They apply only to those policies that renew or take effect between July 1 and September 30. The largest group of policies renew in the quarter beginning April 1, and for those accounts health insurance premium increases averaged 1.9 percent.