The Massachusetts unemployment rate ticked upward to 6.7 percent in December, the seventh straight month that the rate held steady or increased, state officials said Thursday.

The jobless rate has slowly risen from 6 percent since May and added a tenth of one percentage point last month. But the state also added 7,500 jobs in December and 51,000 jobs last year. That helped to trim the unemployment rate from 6.9 percent a year ago and a peak of 8.7 percent in October 2009.