Airbus bought *most* of the C-series in the formation of a joint venture. Bombardier retains a 33.58% of the JV and can oblige Airbus to buy it in 2026 (and vice versa Airbus can oblige Bombardier to sell), or the parties can both agree to a sale earlier.
From
https://www.reuters.com/article/us-b...-idUSKBN1ZF1F2 describing the ownershop of the C-series programme:
Under the terms of the 2018 deal, Bombardier could oblige Airbus to acquire its 33.58% stake in the program in 2026 at market value or Airbus could oblige Bombardier to sell the stake. Still, Bombardier has previously said the parties are free to transact earlier if they both agree.
...
Airbus, which has a 50.6% stake in the A220 program, said it remained committed to funding the jetliner on its way to profitability.
....
A spokesman for the economy minister in the Canadian province of Quebec, which holds a 16.36% stake in the A220 program, declined to comment.