Some 100 new positions are to be created in Co Wexford over the next five years.
Bermuda-based Opus Fund Services is to establish a second Irish site in Enniscorthy.
The company is a privately owned, global fund administrator.
The project is supported by the Irish Government through IDA Ireland.
Founded in 2006, Opus announced the official launch of its European fund administration business in Dublin earlier this year.
The firm has selected Enniscorthy's historic former court building as its second location.
The expansion is on foot of accelerated growth of its North American business that has seen it increase its global headcount by over 50% year to date.
The new roles will be for experienced financial service professionals and qualified accountants, with a working knowledge of fund accounting or financial reporting.
Opus regional CEO, Christian Pollard, says: "With the significant growth of our client base over the last three years, and the continuing strength of our new business pipeline, we are always on the lookout for opportunities to add experienced talent to our footprint.
"County Wexford offers a strong pool of well-educated fund administration professionals and we are looking to speak with individuals that will thrive in a fast-paced business who are keen to join our mission to build the fund administrator of the future."
Minister of State at the Department of Finance, Michael D'Arcy adds: "Wexford has so much to offer, with easy access and proximity to the major urban centres of Dublin, Cork and Limerick, together with our connectivity and pro-business climate.
"The creation of 100 jobs in Enniscorthy is a huge boost for the town, to County Wexford and indeed to the south east region."
Opus has USA offices in New York, Chicago, San Francisco, and internationally in Bermuda, Manila, Halifax and Dublin.