GREENSBORO, NC (AP) FedEx cleared a significant hurdle in its effort to build a cargo hub here as state regulators issued an air-quality permit for the project.

The state Division of Air Quality issued the permit for Piedmont Triad International Airport after concluding that the hub’s flights, loading equipment and vehicle traffic would not create excessive carbon monoxide.

The recent decision comes a week after the state said it was close to issuing a water-quality permit and a month after a federal court refused to order further research on the hub’s environmental impact.

The airport needs only one more environmental approval, a federal water-quality permit, though it also faces at least one state court challenge that might have to be resolved before work could start.

"We’ve worked hard for the last five years to get to this point, and now it seems like we’re making some headway,’"said Mickie Elmore, the airport development director.

Memphis, TN-based FedEx wants to open a $300 million, cargo-sorting hub at the airport by 2009. The project would include a new, 9,000-ft. (2743.2 m) runway at PTI parallel to the airport’s existing main runway.

Hub opponents will discuss whether to appeal the latest permit, said Mark Warren, executive director of the Alliance for Legal Action, a nonprofit organization raising money to fight the project.

Hub supporters say the hub would create jobs and help the Triad’s economy. Opponents counter that the hub would be noisy and dirty.

Air-quality officials studied only carbon monoxide levels and found they would be acceptable. The state measured carbon monoxide at 28 spots in and around the airport. It then projected how pollution would increase based on the hub’s estimated operations and historical weather patterns.

Critics said the air-quality review was faulty because the air was not tested in places it should have been and because the state did not consider the pollution that would be created by construction equipment while building the hub.