Dallas-Fort Worth is currently the top office-leasing market in the country, even with a slowdown in transactions.

D-FW topped all U.S. markets for net office leasing for the 12 months ending with the third quarter, according to a new report by commercial property firm Transwestern. With more than 4.5 million square feet of net leasing, D-FW was just ahead of San Francisco and Denver in Transwestern's quarterly office report.

"It's encouraging to see that office demand is broad-based across multiple sectors, with the technology and coworking sectors driving demand as we move later in the cycle," Transwestern research manager Michael Soto said in the report.

D-FW also ranked second nationally for office building. Only New York had more than the area's 7.7 million square feet of construction.

While office construction is widespread in North Texas, a big chunk of what is being built is already spoken for by companies including Pioneer Natural Resources, American Airlines and Charles Schwab.

With the surge in building activity, more than 15 percent of the D-FW office market was empty in the third quarter. Rents were up just 1.5 percent from a year ago.

Source: Transwestern

Nationwide, office rents were up 4 percent from a year ago, and vacancy is just over 10 percent.

Net office leasing nationally totaled more than 22 million square feet in the third quarter, fueled by the strong economy.

"Real gross domestic product increased at an annualized 3.5 percent, according to first estimates, and personal consumption contributed 2.7 percent to that rate," said Ryan Tharp, Transwestern's director of research. "Because inflation has remained in line with the Federal Reserve's target of 2.0 percent, consumer and business confidence should keep the office market healthy well into 2019."

Year-to-date net absorption in the office market was 17 percent higher at the end of the third quarter than it was for the same period last year, according to Transwestern.

D-FW, San Francisco and Denver, combined, accounted for the biggest share of net leasing.