The European Union's executive body agreed to approve the intended merger after executives of the combined carrier agreed to give up one daily takeoff and landing slot between London Heathrow Airport and Philadelphia International Airport, the commission said in a statement.
US Airways currently operates one daily flight between London and Philadelphia, while American's Oneworld Alliance partner British Airways operates two daily flights between the cities.
"The commitments include a corresponding slot at London Heathrow as well as far-reaching feeder arrangements to induce entry by a new competitor on the route," commission Vice President for Competition Policy Joaquin Almunia said in a statement.
"We are therefore satisfied that the competitive dynamics will be maintained so as to ensure choice and quality of air services for passengers on this route," he said.
AMR Chairman, President and Chief Executive Officer Tom Horton said: "We are very pleased that the EU has approved the merger between American Airlines and US Airways. This represents one of the final milestones on our path to becoming the new American Airlines."
Horton will be chairman of the combined company.