Pharmaceutical giant Pfizer is to invest 100 million euro at two of its sites in Ireland.
Up to 250 construction jobs will be created as the facility in Clondalkin, Dublin, and its plant in Ringaskiddy, Cork, are upgraded to support manufacturing of new drugs.
Pfizer said the work will enable the sites to expand capacity and begin producing more advanced, complex therapies to deal with some of the most devastating and difficult to cure diseases.
Some 77 million euro is being invested in the Grange Castle site in Clondalkin and 23 million euro in Ringaskiddy.
The two sites together employ more than 1,400 staff. Pfizer has 3,200 employees across six sites in Ireland.
The Grange Castle investment, to be completed by 2015, will double productivity in the manufacturing of Pfizer's rheumatoid arthritis treatment while the Ringaskiddy site will focus on some of the company's newest medicines in cancer and other future medicines.
Richard Bruton, Jobs Minister, said the investment was the right step in allowing Pfizer to grow its business in Ireland.
"I am determined to ensure that we build on such success and provide the opportunities for further growth in this sector and create the jobs we so badly need," he said.
Dr Paul Duffy, vice-president of Pfizer, said: "There is opportunity for Pfizer's Irish sites to attract the development of new medicines, while also continuing to manufacture existing, important medicines."
The investment is backed by IDA Ireland. Barry O'Leary, IDA chief executive, said: "Over the last 45 years, Pfizer has continued to innovate and transform its products to cater to the changing demands of its customers. The Ringaskiddy site was Pfizer's first manufacturing facility in Ireland almost 45 years ago - it is fantastic to see the work at that site evolve into hi-tech manufacturing."