The rumored merger talks between United and American Airlines could create an unprecedented concentration of power in the commercial aviation industry.
The airline created by merging the No. 1 and No. 2 carriers would control roughly 40% of US capacity when the available seats are adjusted for miles flown. That degree of consolidation would worry rivals, which could be forced to pursue deals of their own.
It could also raise costs for the millions of passengers who book flights on virtually any US airline, according to airline experts.
“The idea that we would have one airline responsible for four out of ten flights