The creation of more than 350 new jobs by a technology firm based in Newry represents a multimillion-pound boost to the economy, it has been claimed.
First Minister Peter Robinson and Deputy First Minister Martin McGuinness welcomed the announcement by First Derivatives.
The company already provides software, risk management systems and consulting services for global financial institutions, but is expanding its core capital markets consulting business.
Invest NI has offered £4.3 million of support towards the expansion project, but Mr McGuinness said the wages accompanying the jobs would feed millions into the local economy.
"First Derivatives is part of an important and growing hub of technical expertise in financial services which continues to attract international attention and investment at a critical time for our economy," he said.
"The new jobs will generate over £13 million in salaries annually which will feed into the local economy.
"This is an investment which will have a very positive knock-on effect for our growing financial services and technology sectors."
Mr Robinson said: "First Derivatives is one of our most successful indigenous software companies, which has fuelled its growth by continuously developing and delivering innovative products and services in the complex and technically challenging financial services arena."
First Derivatives is one of the fastest-growing firms of its kind in the world and its clients are largely Global 100 financial institutions.
The company's chief executive Brian Conlon said: "With this expansion we are substantially increasing our capacity in the area of capital markets consulting with the aim of growing our global business significantly over the next three years."