(Reuters) - Korean Air is in talks over the purchase of at least 10 Boeing 777X jetliners in a potential tilt back towards its traditional U.S. supplier after placing a major order with European rival Airbus, two industry sources said.

The sources said discussions between Korean Air and Boeing ( BA ) on a purchase of the 777X, an upgrade of the 777 mini-jumbo already used by South Korea's largest carrier, were ongoing.

A third industry source with knowledge of the matter said Korean is in continuous discussions with Boeing ( BA ) on potential orders but does not have immediate firm plans to take new 777s.

Korean Air did not have an immediate comment. Boeing ( BA ) declined to comment and referred any fleet queries to the airline.