American is the nation's third-biggest airline and US Airways ranks fifth by passenger traffic. Together, they would be bigger than current world leader United Continental Holdings Inc., although United would remain slightly larger if regional operations such as United Express and American Eagle are counted.
US Airways is the product of a 2005 merger with America West, which was smaller but controlled the deal and took over the bigger company's name. It has been pursuing a merger with American since shortly after AMR filed for bankruptcy protection in November 2011.
AMR sat out the last several rounds of consolidation in the airline industry and lost its perch as the world's biggest airline in 2008. Its last major acquisition was TWA, which was bankrupt at the time, in 2001.
Associated Press Airlines Writer Joshua Freed in Minneapolis contributed to this report.