Florida Attorney General Pam Bondi says the state joined a lawsuit to block a proposed airline merger because it would harm consumers.
Florida is one of six states that joined with the U.S. Department of Justice to stop the proposed merger of American Airlines and US Airways.
Bondi in a statement called the merger "anti-competitive." She said 20 percent of the "problematic" flight routes associated with the merger would affect Florida.
She said the lawsuit could save consumers from potential multi-million dollar increases in prices and fees.
The decision of Florida to join the federal government is noteworthy since the state has battled the U.S. Department of Justice on President Barack Obama's health care overhaul and voting rights.
Executives of the two companies have vowed to challenge the lawsuit.