Amgen Inc., which recently announced the closure of one of its West Greenwich plants, yesterday canceled plans for a $1-billion manufacturing plant in Ireland and will eliminate all 75 company jobs in that country.

The decision is linked to the “evolving business environment,” the Thousand Oaks, Calif.-based company said in a statement issued by its Irish operation. Amgen, the world’s biggest biotechnology company, said it would shut down its operations in Ireland while plans for the plant were postponed “indefinitely.”

The announcement comes on the heels of the company’s decision to close one of its two Rhode Island drug manufacturing plants and lay off 450 employees.

Amgen in early 2006 said it would spend more than $1 billion on the new Irish manufacturing facility, which would have employed about 1,100 workers in Cork. The plant was intended to produce drugs such as its Aranesp and Epogen anemia treatments, the company said at the time.

Amgen shares have dropped 18 percent this year after studies showed the anemia treatments raised the risk of heart attack, stroke and death at high doses. The stock regained some losses in the last month after the U.S. Food and Drug Administration said the medicines should continue to be given to patients at a maximum limit.

For Ireland, the company’s decision may raise concerns about the economy at a time when a cooling housing boom is already slowing growth. The International Monetary Fund last month warned that the economy may be threatened by inflationary pressures and declining competitiveness that could deter investment.

“Amgen’s decision has been made as a result of a review of Amgen’s operations and is based purely on developments related to the company’s global business,” Irish Trade Minister Micheal Martin said in a statement. It is “in no way related to the economic or competitive environment in Ireland.”