Texas is leading an effort among 19 attorneys general to join the Department of Justice (DOJ) in its investigation into American Airlines Inc. merger with US Airways Group Inc.

The merger, announced in February, is set to create the world’s largest airline, valued at $11 billion. A judge approved the merger in March, and the two companies hoped it would be finalized in September.

With the creation of the world’s largest airline, there comes obvious antitrust concerns from the DOJ. But the states are also worried about reduced revenue if they lose their hubs due to the transaction. US Airways has hubs in Philadelphia; Charlotte; Washington, D.C.; and Phoenix. American has hubs in Dallas-Fort Worth, New York, Miami, Chicago and Los Angeles. Some of the states are also concerned the merger would mean cutbacks to smaller cities.

While Texas is leading the effort, other attorneys general involved in the probe include those from Arkansas, Arizona, California, Washington DC, Florida, Iowa, Illinois, Minnesota, Mississippi, Nebraska, New York, Oklahoma, Pennsylvania, South Carolina, Tennessee, Virginia, Wisconsin and West Virginia.

Read more about this investigation on Reuters.

For more InsideCounsel stories about American Airlines merger with US Airways, see:

American Airlines files plan to exit bankruptcy

American Airlines-US Airways merger approved

American Airlines, US Airways announce $11 billion merger

American Airlines wants more time to reorganize

US Airways and American Airlines may merge soon