) --The Department of Transportation has given tentative approval to
and three other partners to more closely coordinate their trans-Atlantic operations.
But in a news release Saturday, the DOT said that in order to protect competition on routes between the U.S. and London's Heathrow Airport the partners must make four pairs of Heathrow slots available to competitors for new trans-Atlantic service.
American Airlines, the primary subsidiary of
, and British Airways had applied for antitrust immunity on trans-Atlantic routes along with fellow oneworld alliance partners Iberia Airlines, Finnair and Royal Jordanian Airlines.
American Airlines, British Airways and Iberia Airlines plan to operate a joint business between North America and Europe.
The DOT said it had tentatively determined that granting antitrust immunity to the alliance would provide consumers with benefits including lower fares on more routes and better schedules.
But it also said the alliance could hurt competition on some routes between the U.S. and Heathrow, which is the oneworld alliance's primary hub. That's why the department ordered the alliance members to make Heathrow slots available to competitors.
The DOT is allowing for a 60-day comment period before it makes the tentative decision final.
The oneworld alliance competes with the Star Alliance and the SkyTeam alliance.
Shares of AMR closed Friday up 22 cents at $8.71.
This article was written by a staff member of TheStreet.com.