American Airlines, British Airways and Iberia Tuesday received final approval from the U.S. Department of Transportation to form a joint venture to closely coordinate schedules and share revenues on flights between North America and Europe.

The European Union approved the partnership on July 14.

American and British Airways, founding partners in the oneworld alliance, had sought for 14 years to gain antitrust immunity for a partnership that would enable them to jointly market and divvy up revenues on trans-Atlantic flights. British Airways is merging with Iberia, a recent addition to the proposed venture.

Although the rival SkyTeam and Star alliances gained the right to form joint ventures on those routes, American and British were twice barred from combining operations. The regulatory setbacks placed oneworld at a competitive disadvantage, the carriers contended. Opponents argued that regulators would cause irreparable harm to the market by allowing two of the largest competitors to set prices.

“We are pleased that U.S. and E.U. regulators have approved our long-sought-after alliance proposal,” said Gerard Arpey, chairman and CEO of AMR Corp., the president of American Airlines.

The oneworld partners have drawn strong opposition over the years from Sir Richard Branson’s Virgin Atlantic, which is dwarfed by British Airways at Heathrow. Combined, British Airways and American would control 47 percent of landing slots at Heathrow, to Virgin’s 3 percent.

In response to the E.U.’s approval of the venture earlier this month, Virgin warned that British and American would use their new market clout to crush competition and raise prices. The two carriers control 68 percent of capacity from Heathrow to Chicago’s O’Hare International Airport.