American Airlines president Scott Kirby has quit after 20 years to join arch rival United Continental Holdings.

He is being replaced at American by former chief operating officer Robert Isom.

United confirmed Kirby’s appointment in the newly created role of president.

He will be responsible for United’s operations, marketing, sales, alliances, network planning and revenue management, reporting to CEO Oscar Munoz.

Kirby was president of American Airlines since the merger with US Airways in 2013 and was described as a “key member” of its management team more more than 20 years.

Munoz said: “Scott is a proven leader, whose deep airline experience and expertise will further accelerate our efforts to build the best airline in the industry.

“Scott’s appointment, along with other recent leadership announcements, is the culmination of the formation of my senior leadership team. This is just the latest step in our mission to be an agile and innovative industry leader.”

Kirby said: “I am honoured to be joining United at this important and exciting time and to have the opportunity to help accelerate the momentum the airline has achieved over the past year.

“I see real opportunity to build on the airline’s vast global network and, along with my 86,000 United teammates, create the world’s best airline for employees, customers, and shareholders.”