Pharmaceutical company Pfizer has confirmed that it is to cut 177 jobs at two of its plants in Co Cork.

The company said the cuts are in response to a fall in demand for some of its medicines, and the need to reduce costs in line with that.

However, the company said Ireland remains a key strategic location.

The company's revenues have fallen as a result of a number of Pfizer drugs either coming off or about to come off patent.

The ending of patents was expected to have an impact on its operations in this country.

Pfizer is one of the most successful and longest-established multi-nationals operating in Ireland.

The company employs 900 people in Cork and a total of about 4,000 around the country.

Pfizer Vice President Paul Duffy said that the company will seek compulsory redundancies, should it not attain the 177 redundancies at its two Cork facilities.

Speaking on RTÉ's News at One, Mr Duffy said that the company will open up a voluntary redundancy scheme and "depending on how that goes, we will determine how many compulsory redundancies we would have to have in 2013".

He added that the company had been doing a review of its capacity requirements in Cork since the end of last year.

Mr Duffy attributed the change in capacity demands to three factors, a shift to high-power drugs which require less capacity to manufacture; that a number of its key drugs, including the cholesterol lowering drug Lipitor, have come off patent; and its need to stay competitive into the future.

However, Mr Duffy said that Ireland remains a key location for Pfizer.

"We have eight locations, we have six manufacturing sites, we have a treasury centre, a services centre and a commercial group, so it's a very varied level of activity. We have invested €200m in our facility in Grange Castle, and we brought four new drugs into the country, three of them into the sites in Cork."

Minister for Agriculture Simon Coveney has said his thoughts are with the Pfizer workers who are to lose their jobs.

In a statement, he said: "Following the decision by Pfizer to reduce the number of staff at its Cork plants by 177 positions, my thoughts are with workers and their families today as they face an uncertain future."

The Fine Gael TD for Cork South Central added: "I hope that the vast majority of jobs losses will be as a result of a voluntary redundancy scheme."