RSM UK is investing heavily into RSM Ireland, with the aim of doubling the size of the firm there in the next three years.
The investment also includes RSM UK acquiring ownership of the business from the current board. The two firms will, however, operate as independent firms.
RSM Ireland will now look to create at least 200 jobs in the next three years under the leadership of Niall May, who becomes the new managing partner in January.
RSM Ireland began as a start-up in 1987 and it is now one of the top 10 and fastest growing accountancy firms in Ireland.