April 24 (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 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 on potential orders but does not have immediate firm plans to take new 777s.

Korean Air did not have an immediate comment. Boeing declined to comment and referred any fleet queries to the airline. (Reporting by Tim Hepher, Joyce Lee and Allison Lampert Editing by David Goodman )