WSJ – The Justice Department has filed suit seeking to block the $11 billion merger of American Airlines’ parent corporation, AMR, and US Airways Group, saying the combined company would reduce competition in local markets and result in higher airfares.

American and US Airways compete directly on more than 1,000 routes where one or both offer connecting service, the government said. The government’s suit says the vast majority of domestic airline routes are already highly concentrated, and the proposed merger would create the largest airline in the world, resulting in four airlines controlling more than 80% of the U.S. commercial air travel market.