The Conference Board Employment Trends Index dropped in August for the second time in the past four months, to 96.7, down from 97.4 in July. Still, figures from August were up 9.4 percent from last year.

"Employment growth has been slow lately, and the Employment Trends Index suggests that it may slow even further this fall," said Gad Levanon, associate director of macroeconomic research at The Conference Board. "However, we still expect job growth rather than an outright decline in the next several months."

The Conference Board aggregates eight components from several government and private sources for its Employment Trends Index. Seven of those eight components received negative responses. Some of the weakened indicators included percentage of respondents who said jobs were hard to get; initial unemployment insurance claims; part-time workers for economic reasons; and percentage of firms with positions not able to fill right now.