Professional services firm Deloitte is to create an extra 300 jobs in Belfast.
Most of the posts will be in the technology end of the company's work.
The expansion will make the city the business's largest UK base outside of London by 2020.
Nick Owen, chairman of Deloitte in the UK, said: "That is testament to the success that the team here has enjoyed since announcing significant expansion plans and the breadth of expertise within the business.
"This commitment by Deloitte reflects the confidence we have in Belfast as a great place to do business and a hotbed of talent, particularly for graduates and school leavers.
"It also demonstrates our continued commitment to social mobility as a core part of our talent strategy and our desire to continue to further deliver on this commitment in Northern Ireland."
In 2014, the firm said it aimed to employ 700 people in Belfast by 2019.
The new target is for 1,000 by 2020.
First Minister Arlene Foster said: "Deloitte is making this commitment based on the talent and quality of staff in Belfast and it is a clear indicator of the confidence that the firm has in Northern Ireland as a business-friendly economy that will continue to grow and attract investment."
Deputy First Minister Martin McGuinness said they were high-quality jobs.
"This announcement today demonstrates the Deloitte determination to invest in our economy and the scale of their ambition.
"Investment by companies like Deloitte signals to other potential investors we continue to offer an attractive 'pro-business' environment."