The joint venture by Europe’s Air France-KLM and Delta Airlines in the US to share revenues and costs on transatlantic routes was strengthened this week when Italy’s Alitalia announced that it would be joining the team. With the Italian flag carrier on board, the venture, which is not a merger, will control just over a quarter of the capacity moving across the Atlantic. It is estimated that the team will achieve annual revenues of around $10 billion.

The four airlines are already bound together as members of the SkyTeam alliance. However, the transatlantic venture means wider cooperation on routes between Europe and North America. As many as 55,000 seats on approximately 250 aircraft will be offered to passengers everyday, according to a joint statement issued by the members of the venture.

At a news conference in Rome, attended by each of the airline’s chief executives, Rocco Sabelli, Alitalia’s boss, said that by joining the group it did not mean that the flag carrier was intending to merge with Air France-KLM.

Air France-KLM failed to buy Alitalia but ended up owning a quarter of the company in January last year. The airline is now controlled by a group of Italian investors. Sabelli added that the joint venture had all the benefits of an actual merger, but meant that each airline was still separate, only remaining within the partnership for as long as it made sense to do so.

In a statement, Mr Sabelli also pointed out that in competitive and strategic terms, the transatlantic market was becoming increasingly important.