NEW YORK (TheStreet) -- Drug maker Pfizer (PFE) - Get Report announced Tuesday that it will slash 6,000 jobs as it shutters eight plants around the world.

The closures will occur in Ireland, Puerto Rico and the U.S. by the end of 2015. Pfizer will also reduce operations at six other plants over the next several years.

Pfizer said back in April that it will eliminate 20,000 jobs as part of its integration of Wyeth, which it acquired last year in a $68 billion deal.

Cramer on Pfizer and Human Genome

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Last week, Pfizer also revealed that it may relocate some of its New York employees to Pennsylvania and New Jersey, resulting in additional job losses. At the time Pfizer said it was putting a New York office building up for sale, but that its headquarters will remain in Manhattan.

"We have a tremendous global workforce and some of the best manufacturing facilities in the industry," said Nat Ricciardi, Pfizer's president of manufacturing, in a press release Tuesday. "But we must continue to adjust to the fast-changing and extremely competitive environment in which we operate."

The company owns 78 plants around the world and employs about 116,000 people.

-- Written by Jeanine Poggi in New York

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