Construction’s unemployment rate fell in June to 4.6%, the lowest mark since October 2006, but the industry gained no jobs during the month, the Labor Dept. has reported.

Construction economists say the lack of jobs growth may reflect a shortage of qualified workers and the departure of construction workers for jobs in other industries.

The Labor Department's  Bureau of Labor Statistics said on July 8 that construction’s June jobless rate declined from May’s 5.2% and also dropped from the year-earlier 6.3%.

The unemployment rates aren’t adjusted for seasonal differences.

But the negative note in the BLS monthly report was that construction’s total workforce showed zero gains in June.

The jobs picture was mixed among industry segments. Specialty trade contractors recorded an increase of  8,400 jobs in June, according to preliminary BLS figures. But buildings construction lost 3,700 positions and heavy-civil construction shed 3,900.

Architectural and engineering services, a separate BLS industry category, added 2,400 jobs during the month.

Anirban Basu, Associated Builders and Contractors chief economist, said in a statement, "As has been in the case for many months, the most significant sources of weakness in construction activity and hiring relate to public spending." He said that even though a new federal highway-transit measure was enacted last December, many transportation contractors have been reducing their workforces.

Basu also said the reduction in overall construction employment may be a signal that workers and those seeking work are moving to non-construction fields.

Ken Simonson, Associated General Contractors of America chief economist, said in a statement that the low construction jobless rate  and gains in hourly earnings and weekly hours worked "suggest there is a dearth of qualified workers to hire, not a deliberate pullback in hiring."

AGC, which for months has been pointing out the industry's workforce shortage, also urged Congress to pass legislation dealing with technical and career education.

Over all, the June U.S. unemployment rate rose to 4.9% from May’s 4.7%  but dipped from June 2015’s 5.3%, BLS said. The economy added 287,000 jobs last month.

Story updated 7/8/16  p.m. to include industry economists' comments.