CHICAGO, March 12 (Reuters) - Large U.S. airlines stood by Boeing Co's 737 MAX on Tuesday, even as an increasing number of nations decided to ban it, with Southwest Airlines Co and American Airlines Group Inc saying their fleet data showed the plane was safe.
Britain, one of the industry's most established regulators, joined a growing wave of countries that suspended the 737 MAX aircraft on Tuesday, the worst setback yet for Boeing, following a fatal crash in Ethiopia on Sunday.
The disaster, which follows the fatal crash of another 737 MAX jet in Indonesia five months ago, has caused alarm in the international aviation industry and wiped billions of dollars off the market value of Boeing, the world's biggest planemaker.
The 737 MAX went into service in 2017 and has bigger engines than older Boeing aircraft.
Southwest, the largest operator of 737 MAX 8 aircraft, said its 34 MAX 8 jets produce thousands of data points during each flight, which are constantly monitored.
"To date, we have operated more than 41,000 flights and have corresponding aircraft data that indicates the effectiveness of our operating standards, procedures, and training," spokeswoman Michelle Agnew said in an emailed statement.
American Airlines released a similar statement on Monday, saying extensive flight data collected from its fleet gave it confidence in the safe operation of all its aircraft, including the 737 MAX 8.
An American official on Tuesday said the airline's position remained the same.
American, with 24 MAX 8 planes, said it has been sharing its data with the U.S. Federal Aviation Administration, in coordination with the Allied Pilots Association, a union that represents American's pilots.
United Airlines, which does not fly the MAX 8 but operates another model in the series, the MAX 9, also reiterated its confidence in its pilots "ability to fly the aircraft safely."
Both American and United's flight attendants' unions have expressed concern this week about flying the 737 MAX. (Reporting by Tracy Rucinski; Editing by Bernadette Baum)