The company employs 3,600 people at a number of sites in the area and is the largest manufacturer in Northern Ireland, with a history dating back to the 1930s when Shorts established its first factory in Belfast.
Bombardier said it was creating a streamlined aviation unit focused on operations in Montreal, Mexico and Texas.
As a result, it said it would pursue the sale of its aerostructures businesses in Northern Ireland and Morocco, describing them as “great businesses with tremendous capabilities”.
All of its sites in Northern Ireland – in Belfast, Newtownabbey, Newtownards and Dunmurry – are affected.
The company said: “Bombardier is committed to finding the right buyer – one that will operate responsibly and help us achieve our full growth potential.
“We understand that this announcement may cause concern among our employees, but we will be working closely with them and our unions as matters progress, and through any future transition period to a new owner.
“There are no new workforce announcements as a result of this decision, but our management team will continue to drive ongoing transformation initiatives to improve productivity and increase our competitiveness.”
Business secretary Greg Clark said the Belfast plant was “one of our most important aerospace facilities in the country and a vital asset in the UK’s leading aerospace sector”.
He added: “The government will work with potential buyers to take this successful and ambitious business forward.”
DUP leader Arlene Foster said Bombardier was “an integral part of the Northern Ireland economy” and that the decision to sell would be “unsettling for the workforce”.
The announcement comes after Bombardier said in November it was cutting 490 jobs in Belfast as part of a global drive to cut costs.
GMB, the trade union, demanded reassurances over the future of the company’s workforce in Northern Ireland, who had already suffered a “terrible year” after months of uncertainty following trade friction with the US and the job losses.
Michael Mulholland, a GMB organiser, said: “Bombardier jobs are absolutely vital to Northern Ireland’s economy and it’s time workers were treated with the respect they deserve.”
In 2017, the Northern Ireland operation came under threat from US proposals to slap 292% tariffs on Bombardier C-Series passenger planes, whose wings are made in Northern Ireland – but the plans were later blocked by the US International Trade Commission.
Bombardier bought the Shorts business from the UK government in 1989 and has since invested more than £2.7bn.
Today it specialises in parts including wings, engine systems and fuselages.
Its parts are used both for Bombardier aircraft and for customers including Airbus, General Electric, Pratt & Whitney and Rolls-Royce.
Paul Everitt, chief executive of aerospace trade body ADS, said Bombardier “plays a critical role in supplying components for major aircraft models”.
He added: “The announcement made today will be unsettling for the workforce in the short-term and it will be important for government, industry and the trades unions to work together to help secure the long-term ownership of the business.
“The skills, experience and capability in the Belfast operation means there is every reason to be confident of a positive long-term future for the business and its supply chain in Northern Ireland.”