Washington —  The Justice Department and several states have filed suit to block the $11 billion merger between American Airlines and US Airways, saying it would cut competition in the industry.

The move on Tuesday, Aug. 13, effectively dragged to a halt the long-pending merger to create the world’s largest airline as American Airlines and its parent AMR Corp exit bankruptcy restructuring.

The merger “would substantially lessen competition for commercial air travel in local markets throughout the United States and result in passengers paying higher airfares and receiving less service,” the Justice Department said in a statement.

The department added that the U.S. airline industry was already “highly concentrated,” and that after the merger four airlines would control more than 80 percent of the commercial air travel market.