VIAGRA maker Pfizer said last night it was selling its plant in Northumberland, placing 571 jobs in jeopardy.

The global pharmaceutical company said it was shedding up to 400 jobs at Sandwich, in Kent, and the site at Morpeth would be sold.

The company said it was confident the North-East plant would be sold as a going concern.

A review by the company found that the capacity of the site was not needed.

The factory manufactures medicines, tablets and capsules for female health and arthritis medicines.

Pfizer said in a statement: "Efforts will now focus on finding a buyer for the site, which currently employs 571 people.

''In the case of both sites, every effort will be made to mitigate impact on Pfizer colleagues and the local communities. To this effect, the company will work closely with the Department of Trade and Industry and relevant local agencies.''

A spokeswoman said the Morpeth site had a skilled workforce and a history of surviving mergers and acquisitions and the company was confident of finding a buyer.

Pfizer said it had been conducting an exhaustive review of its global manufacturing requirements since it acquired Pharmacia in 2003.

George Cowcher, chief executive of the North East Chamber of Commerce, said: "Pfizer and similar global players are woven into the fabric of the region's economy and we must do everything in our power to maintain that relationship."