Anirban Basu, the Associated Builders and Contractors' chief economist, said that the BLS report “offers hope that the industry is experiencing a positive trend in activity.”

But Basu cautioned that much of the early 2011 economic momentum “has been lost during the past seven months, with the implication being that the current pace of recovery in nonresidential construction is unlikely to last.”

Stephen Sandherr, Associated General Contractors of America CEO, said that much of the drop in the construction jobless rate came from workers leaving the industry, not from those coming back to construction work.

Sandherr said, “With private-sector demand inching back up, the construction industry is finally on the brink of recovering from years of hardship and job losses.” But he added, “If Washington continues to cut infrastructure funding instead of addressing out-of-control entitlement spending, the industry will lose whatever momentum it picked up in September.”

The BLS jobless rates for construction and other industries are not adjusted for seasonal variations. Construction’s seasonal swings can be significant, as the volume of projects rises in summer and early fall and drops off in the winter.

The overall national jobless rate for September held at 9.1%, the same as in July and August, BLS said.