Northern Trust is to create 300 jobs in Limerick over the next three years.
It will bring the Limerick workforce at the US financial services company to over 1,000 by 2017.
Northern Trust is a fund administration company with six trillion US dollars in assets under its management and annual revenue of over $4bn.
It has had a presence in Ireland since 2000. The company employs a further 500 staff in Dublin.
“Northern Trust is an extremely important employer in the Mid-West and its planned expansion is a major vote of confidence in Limerick which is fast becoming the location of choice for the highly skilled financial services sector,” said Pat Daly, Limerick council's director of economic development.
"The roles that are being announced today are also reflective of the level of skills and business infrastructure that are available here, particularly the strength of our graduates."