July 11 (Reuters) - Boeing ( BA ) is nearing a potential

sale of some two dozen 777X jets to Korean Air in a

roughly $4 billion to $6 billion deal that could be finalised as

early as July's Farnborough Airshow, industry sources said.

South Korea's largest carrier has been in talks over a

potential return to its traditional supplier of long-haul

aircraft for months after placing a surprise order for 33 A350

jets from Boeing's ( BA ) European rival Airbus in March.

The sources said the potential new order could involve as

many as 20 to 30 of the 777X aircraft, which are worth some $198

million each after typical market discounts, according to

estimated delivery prices from Cirium Ascend.

"We are discussing with manufacturers but nothing has been

confirmed yet," an airline spokesperson said.

Boeing ( BA ) said it does not comment on commercial discussions

and referred any queries on Korean's intentions to the airline.