Monster Worldwide Inc, an online careers and recruiting firm, said its employment index slipped 1.9 percent to 153 points last month from 156 in August. The index was up more than 3 percent from 148 a year ago.

Online demand was higher compared to a year ago in 14 of the 20 industries covered by the report, and was up in 19 of the 23 occupational categories.

The number of openings available in retail trade was up more than 12 percent from last year, leading the growth among industry sectors, while demand for construction workers also accelerated.

Public administration had the steepest annual decline, down close to 15 percent.

The report was another look at the jobs market ahead of the government's non-farm payrolls report later on Friday. Job growth is expected to have picked up slightly in September.

The Monster Employment index is a monthly analysis based on a selection of corporate career sites and job boards. The margin of error is approximately plus or minus 1 percent.