USA Today article:
The move by Bombardier could possibly circumvent duties being imposed on the C Series. The C Series headquarters will remain in the Montreal area but a second assembly line for the 100- to 150-seat plane will be set up at Airbus' facility in Mobil, Alabama, so the plane can be sold in the United States.
Enders said the talks started in August and were not motivated by what competitors are doing. He rejected a deal to acquire the C Series three years ago but said circumstances have changed, saying the plane is now certified and receiving rave reviews.
Airbus is not assuming any debt as part of the deal and it has an option to buy out Bombardier after 7-1/2 years and the Quebec government in 2023.