United is the second-largest carrier, handling approximately 19 percent of passengers.
American, on the other hand, the second-largest carrier, said it had 921 incidents last year, a 200 percent increase from 1994.
United, the second-largest carrier, eliminated 20,000 jobs and reduced its schedule by 26 percent.
Meanwhile, American, which is the country's second-largest carrier, and its pilots still have to work out their differences or the airline could face more disruption.
President Clinton urged the nation's second-largest carrier and its pilots' union to resolve the dispute.
That move leaves United, the second-largest carrier, as the leader in the talks.
United Airlines, the nation's second-largest carrier, said that it also may have to seek bankruptcy protection.
United, the nation's second-largest carrier behind American, is one of the worst off of the airlines.
The sources said the pilots could end up with a controlling stake in the nation's second-largest carrier.
The move by United, the nation's second-largest carrier, pushed up the price of its stock by $9.875, to $137.