As of Thursday afternoon, the company had not filed the 60-day closing notice required by law.
Express Scripts, which reported $24.7 billion in revenue and $827.6 million in profit in 2009, said it would move the work to its new facility in St. Louis.
"Having looked at mail volume, overcapacity, and the superior technology, equipment, and space available in the St. Louis . . . ESI has concluded these factors dictate the closure of Marshall Lane," the company wrote in an Oct. 7 letter to the Service Employees International Union.
The company may also close the Street Road facility, spokesman Thom Gross said.
The union said the company would not have the capacity for big contracts announced this year if it closed the Bensalem facilities.
The union's contract expires Dec. 15. Haynes, who is negotiating for the union, said that the company had sought $8.8 million in concessions, and that the union had provided $8 million.
In March, she said, Express Scripts officials told the union that it was considering closing both facilities. Gross, while declining to discuss negotiating terms, said current union negotiations over wages would have no effect on the decision to close Marshall Lane, but would influence the decision to keep the larger Street Road facility open.
Except for a small group in Albuquerque, N.M., the Bensalem workers are the company's only union employees.
In 2009, Gross said, the company considered adding jobs, investing in technology, and expanding at the former Jones New York apparel company headquarters in nearby Bristol Township. But, he said, the company was unable to reach an agreement with the union.
"We did give them $3.5 million in concessions, but they declined them," Haynes said. "They never gave us a goal."
Bristol Township Councilwoman Tina Davis said the state had offered to turn the area into a low-tax business-development zone to keep the work in the region.
Last week, Express Scripts workers traveled to Washington to speak with members of Congress and to lobby the Defense Department to drop its pharmacy-benefit contract with Express Scripts.
The union itself, which uses the company for its pharmacy-benefit plan, said it would bid out its $3 million contract.
"We have to make it more expensive for them to shut it down than for them to keep it open," SEIU organizer Bill Ragen told the Trevose gathering.
To the workers, the planned closing of the Marshall Lane site is disheartening.
In June, the company thanked Bensalem's crew for setting a single-day production record, shipping 90,050 prescriptions June 17.
Gross said competitive wages and efficient facilities helped all its customers, including unions, by keeping pharmacy costs down.
He said it was unclear whether Bensalem workers would be offered positions in St. Louis.
Contact staff writer Jane M. Von Bergen at 215-854-2769 or firstname.lastname@example.org.