Pittsburgh International Airport has biggest monthly passenger increase since 2011

Pittsburgh International Airport in April recorded its largest monthly jump in passenger traffic since 2011, at 11.2 percent, according to an airport news release.

The airport credits the increase largely to Southwest Airlines, which added service to St. Louis and Los Angeles, capacity on flights to Orlando, new seasonal flights to New Orleans, and continued seasonal service to West Palm Beach for an a extra two weeks in April.

New flights on Frontier and OneJet and an increase in capacity on United flights to Chicago also contributed.

"These numbers are impressive and continue a four-year trend of growth at Pittsburgh International," Allegheny County Airport Authority CEO Christina Cassotis said. "We are encouraged by the increases in flights, seats and passenger traffic that indicate confidence in our market by the airlines."

More than 30 percent of all passengers traveling through the airport in April were flying Southwest, the release said.

American Airlines had the second most with 27 percent, followed by Delta at 16 percent and United at 14 percent.

Theresa Clift is a Tribune-Review staff writer. Reach her at 412-380-5669, tclift@tribweb.com or via Twitter @tclift.