Wilmington will remain as AstraZeneca's North American headquarters, with about 2,000 employees, but that is down from a high of more than 5,000.
AstraZeneca had considered closing its Delaware operations, U.S. Sen. Tom Carper (D., Del.) told the Wilmington News Journal.
"A number of options were under consideration," company spokesman Tony Jewell said. "Ultimately, we decided to keep Wilmington as our North America commercial headquarters."
In a statement, Delaware Gov. Jack Markell said: "I am greatly disappointed by the job losses at the company and for the employees whose lives will be painfully and directly affected."
AstraZeneca chief executive officer Pascal Soriot took over Oct. 12. This latest part of remaking the company was not restricted to Delaware.
AstraZeneca will move about 1,600 of the 2,900 jobs in its largest research facility in Alderley Park, England, which has operated for the last 40 years, to other British facilities. The company will move its headquarters from London to Cambridge, England, where it will build a new facility for administration and research.
The company will focus research efforts in Cambridge, Gaithersburg, and Mölndal, Sweden.
"This is a major investment in the future of this company that will accelerate innovation by improving collaboration, reducing complexity, and speeding up decision-making," Soriot said in a statement. "I recognize that our plans will have a significant impact on many of our people and our stakeholders at the affected sites. We are fully committed to treating all our employees with respect and fairness as we navigate this important period of change."
Markell's office said AstraZeneca, which has a manufacturing facility in Newark, Del., had complied by 2005 with the employment requirements of state aid that were tied to the company's move from Pennsylvania, which was announced in 1999. A company official said there were no negotiations with Maryland or Delaware officials about the latest decisions.
Referring to Delaware, State Sen. Chris Coons said: "There is a wide array of innovative companies doing high-end research that could really benefit from the enormously talented scientists and researchers now looking for work."
Contact David Sell at dsell@ phillynews.com or 215-854-4506. Read his blog at www.philly.com/phillypharma and on Twitter @phillypharma.