BANGOR – Pan American Airways is delaying by about a month a shift in flight routes that would take Bangor International Airport passengers to Allentown, Pa., instead of Pittsburgh.

The change was to have occurred next Monday.

Pan Am wants to stop flying from Bangor to Pittsburgh, saying the modification would help avoid a crowded airport that results in frequent delays.

The airline has instead opted to fly into Lehigh Valley International Airport in Allentown. The airport is close to Philadelphia and Trenton, N.J. Eight airlines make 47 departures a day from the airport.

Jeff Russell, BIA’s marketing director, said the shift would provide Bangor passengers with shorter layovers and a greater number of connections to choose from because of the many airlines that serve the airport.

But Russell said Pan American and BIA chose to push back the changeover by about a month because January is slow for ticket sales nationwide. Russell said Bangor flights rarely reach 50 percent occupancy during January.

The new start for the Allentown service is Feb. 10. Passengers will be flown on Pan American’s 727 jets, which seat 149 people each.

The extra month, Russell said, also will allow officials at Pan Am and at both airports to market the new service. In fact, Russell said, he expects to see the Allentown airport advertised in the Bangor area.

Russell said BIA stands to gain from the new service because a 250-mile radius around Allentown includes nearly 25 percent of the U.S. population.

“In order to continue to grow,” Russell said, “we are going to have to be able to stimulate some inbound traffic. We’re tremendously excited about the prospects of the Allentown service going forward. That region is one of our biggest inbound markets in the summertime.”

Russell also said the new service would improve the arrival time of passengers traveling from Bangor to Florida. Because Pan Am plans to leave a jet overnight at Bangor each day, the first flight will leave for Florida earlier, allowing passengers to arrive in Orlando by 11:30 a.m., Russell said.

“It’s a great two-for-one.” Russell said. “We’re picking up a major urban area in addition to our … Florida service,” Russell said.

Pan American also will offer connecting service to Chicago and St. Louis from the Allentown airport.