Oil and gas development in the five-state Marcellus shale region in the Northeast U.S. has generated more than 45,000 new construction jobs, says a study commissioned by building trades and and sector union employers.

The report, sponsored by the Oil and Gas Industry Labor-Management Committee, studied employment data in all or part of Maryland, Pennsylvania, Virginia, Ohio and West Virginia between 2008 and 2014.

Research, conducted by the University of Illinois School of Labor and Employment Relations, was based on data from global industrial market intelligence, National Maintenance Agreement collective bargaining pacts covering 14 trade unions and 2,000 contractors, and building trades employment data.

Data from 1,326 projects, including both union and nonunion labor, were studied, say survey authors Robert Bruno, school director and research assistant Michael Cornfield. Bruno says the findings are based on "all the large capital expenditures and scheduled maintenance activity."

The report says that Marcellus shale development spending in 2014 totals about $6.5 billion to date—up from $5 billion the previous year. More than 4,600 construction jobs were created in 2013, with about 9 million labor hours recorded. This is a 40% increase over 2012, say the researchers.

The study did not break out data on the mix of union and non-union hours worked.

However, non-shale related oil and gas investment fell by 53.7% since 2008, generating just 6.6 million labor hours in 2013 for eight trades studied, the report contends.

The results indicate that Marcellus shale development "has repositioned construction employment in the oil and gas industry," says Bruno, adding that without the shale-related projects, "the region would have experienced substantially higher incidences of construction industry job displacement."

Sean McGarvey, president of North America's Building Trades, the unions' umbrella group, says domestic energy development "is the single biggest contributing factor for job growth in U.S. construction today."

McGarvey and Bruno will discuss the findings at a press briefing on Oct. 16.