Los Angeles County’s unemployment rate hit 13 percent in December for the first time in modern history, state figures released Friday show.

The county’s seasonally adjusted jobless rate was noticeably higher than a year earlier, when it was 12.3 percent, and somewhat higher than November’s revised 12.8 percent, according to the state’s Employment Development Department.

However, in a separate survey of employer payrolls, the county added 4,400 jobs in December from the month before, mostly due to seasonal hiring.

The trade, transportation and utilities sectors saw the largest increase in jobs between November and December, adding 3,800 jobs, mostly in retail trade. The information sector gained 3,700 jobs, with motion picture and sound recording accounting for the bulk of the increase.

Industries reporting the biggest declines over the month were professional and business services, down 3,000 jobs; construction, down 2,400 jobs; and government, down 2,300 jobs.

The closely watched year-over-year payroll jobs figures showed significant improvement in December, showing a drop of only 4,200 jobs over the past 12 months, or 0.1 percent. During the depths of the recession, the year-over-year job losses exceeded 150,000.

The state’s seasonally adjusted unemployment rate was 12.5 percent in December, up from 12.4 percent in November. For the country, the unemployment rate was 9.4 percent in December, down from 9.8 percent in November.