The joint venture represents around 25 per cent of total trans-Atlantic capacity and will see the airlines share revenues and costs to offer more choice in frequency of flights, and to make cost savings.
In a statement the airlines said passengers would benefit from access to a network offering over 200 flights and approximately 50,000 seats a day.
That network is structured around six main hubs: Amsterdam, Atlanta, Detroit, Minneapolis, New York-JFK and Paris-CDG, together with Cincinnati, Lyon, Memphis and Salt Lake City.
Richard Anderson, CEO of Delta Air Lines, said: "The structure of this joint venture, in which we operate as a single business where we consensually develop our strategies and share revenues and costs, provides the incentives for us to collaborate in a way that generates benefits for customers, shareholders and employees of our three airlines.
"Customers will benefit from the unique scope and choices we will offer, while shareholders and employees will benefit from the stronger competitive and financial position of our respective airlines."
The airlines will also cooperate on routes between North America and Africa, the Middle East and India, as well as on flights between Europe and several countries in Latin America.