United Airlines Boeing 787 in emergency landing as inspections ordered

While concerns about its safety could affect passenger perceptions and raise issues with deliveries to other airlines, analysts said flight diversions are not unusual, especially with new aircraft.

"These are the typical growing pains one would expect with a new airplane as it enters service," said Carter Leake, a former military and commercial pilot who is now an analyst with BB&T Capital Markets. "No conclusions can be drawn."

United said the problem occurred with its third 787, delivered on Nov. 27. The airline, which is due to receive two more 787s this month put the passengers on other flights to Newark.

"At this point, we're just looking at this specific plane, not the fleet," said Christen David, a United spokeswoman.

United is the first U.S. airline to put the new carbon-composite 787 into service and flew its first commercial flight with the new jet on Nov. 4.

Shares of ANA dipped 1.1 percent in Tokyo with JAL down 0.1 in line with the benchmark Nikkei 225 index.