Airbus is to take a majority stake in Bombardier's C-series passenger jet programme in a deal that could offer hope to thousands of British workers as it faces a costly US trade dispute.
The European plane maker will acquire a 50.01% stake in the venture and will pay nothing for the holding - but it is expected that the arrangement will lead to savings on production and also make use of Airbus's international reach to boost sales.
It could also help the jet programme overcome a US ruling that it must be subject to heavy import tariffs - after Airbus boss Tom Enders said it had offered to assemble some of the planes at its plant in Alabama for orders by American carriers.
Canadian firm Bombardier employs 4,000 people in Belfast where the wings for the C-Series are made.
There have been fears for those jobs as the company is facing a 220% tariff on a new model of passenger jet and a second preliminary levy of 80% on the exports of its planes to the US.
The dispute centres around claims from US firm Boeing that Bombardier received unfair state subsidies from the UK and Canada, allowing it to sell airliners at below-cost prices in the US.
Davy Thompson, Unite regional coordinating officer, said the union had received assurances that the Airbus deal "will mean that employment associated with the manufacture of C Series wings will remain in Belfast".
He said it "should safeguard the future of C Series production jobs in Belfast for the foreseeable future" - though there were "continued challenges" over jobs linked to other Bombardier contracts in Belfast.
Under the deal - which is subject to approval by regulators - the remaining stakeholders would be Bombardier and Investissement Québec, which would own about 31% and 19% respectively.
Airbus would provide procurement, sales and marketing, and customer support to the CSALP, the entity that makes and sells the jet.
Airbus chief executive officer Tom Enders said: "Not only will this partnership secure the C Series and its industrial operations in Canada, the UK and China, but we also bring new jobs to the US.
"I have no doubt that our partnership with Bombardier will boost sales and the value of this programme tremendously."
"Double the value"
Alain Bellemare, president and chief executive officer of Bombardier, said: "This partnership should more than double the value of the C-Series programme and ensures our remarkable game-changing aircraft realises its full potential."
The C-Series headquarters will remain in Montreal but a second assembly line will be set up at Airbus's facility in Alabama.
Mr Enders said that an aircraft made in a US Airbus facility would not be subject to duties under the US case, AP reported.
A Boeing spokesman said: "This looks like a questionable deal between two heavily state-subsidised competitors to skirt the recent findings of the US government."
It was not clear how the partnership between Bombardier and Airbus might affect the tariff row but Northern Ireland political leaders welcomed the announcement.
DUP leader Arlene Foster described it as "incredibly significant news for Bombardier, Belfast and Northern Ireland".
She added: "Airbus clearly recognise the value of the C-Series. I welcome their interest and investment.
"Having personally supported the aircraft through its development, I'm thrilled there is a bright future ahead following what has been a dark time for staff and management.
"I hope this will safeguard the C Series programme."
East Belfast MP Gavin Robinson added: "Over the last four months, our focus has been the Belfast workforce and securing a successful resolution to this ongoing dispute.
"Whilst there is some way to travel, we will offer our full support in securing the necessary regulatory approvals. The commitment to the Belfast facility is a testament to the ingenuity of the workforce.
"They should be proud that their valuable capability will continue to play a crucial role in C-Series."