The U.S. Department of Transportation has given a green light to changes in the trans-Atlantic joint venture of Airfrance, KLM, Virgin Atlantic and Delta, allowing the four airlines to share information, route planning and profits on the highly competitive routes.
American, British Airways, Iberia and Finnair have a similar agreement, and the new Delta one actually replaces a series of agreements linking Air France/KLM to Delta and Virgin Atlantic to Delta. Alitalia and Czech Airways, part of the original proposal have been dropped, but might become "associate members" later.
Joint venture agreements essentially allow a group of airlines to operate as one on specified routes, giving them a leg up in competition as they can offer more choices, or can avoid unprofitable competition by not all flying the same routes. On the other hand, critics of the plans have long argued that by reducing competiton, prices will ultimately rise. On the Atlantic segment, that has yet to happen, with prices frequently at historic lows.