Airbus says the new line will create 700 jobs by 2026, about half the full-time total when the world's largest jet was built there, while supporting a fabric of thousands of suppliers.
It is the eighth assembly line for the A320 family, with previously announced expansion plans in the United States and China due to bring the worldwide total to 10.
Its opening comes as competition between Airbus and arch-rival Boeing (BA.N) shifts towards production strategy, with both companies struggling to deliver on bulging order books.
Environmental critics say burgeoning sales of the current generation of jets will make it harder to meet climate goals.
Le Maire told Reuters aircraft like the A321 still offered significant savings in emissions compared to jets they replace.
Persons:
Luc Lagardere, Bruno Le Maire, Emmanuel Macron, Le Maire, Tim Hepher, Richard Lough, David Evans
Organizations:
Airbus, French Finance, Boeing, Concorde, Reuters, Thomson
Locations:
TOULOUSE, France, Toulouse, United States, China