American Parent AMR Falls Most Since 2003 on Bankruptcy Concern

American Airlines parent AMR Corp. tumbled the most since 2003, triggering automatic trading halts, on growing concern the third-largest U.S. carrier may be forced to seek bankruptcy protection.

So-called circuit breakers to stop the rout from moving to other shares took effect seven times in less than an hour starting at about 12:58 p.m. in New York Stock Exchange composite trading. Fort Worth, Texas-based AMR plunged as much as 41 percent to $1.75, the lowest in more than eight years.