Allen & Overy (A&O) plans to open an operational support and legal services center in Belfast, the capital city of Northern Ireland, and employ 300 people by 2014 to run it.
Out of them, at least 180 are expected to be transferred from the firm's London office by autumn.
A&O said that relocation packages will be offered to the support staff with the intention of minimizing job losses. They will not be required to leave or relocate before the office is operational in April.
The firm is also in the process of selecting an internal candidate to head up the office. It will soon begin consulting with the current London support staff as to what roles will be transferred to Belfast.
A firm insider said support services such as elements of IT, HR, finance, business services and library could be transferred to the new office.
According to A&O managing partner Wim Dejonghe, the way global legal services are being delivered is changing and the new office will help the firm address the challenge and proactively offer increased efficiencies and alternative resourcing to our clients, but with the reassurance and quality they expect from A&O.
The firm said that Northern Ireland was particularly attractive due to its strong education system and quality of investment incentives.