The aircraft maker said the deal is worth $370 million at list prices, although carriers often negotiate discounts. The planes will be the first Boeing aircraft in Jeju's fleet.

"The 737-800 aircraft exactly matches our long-term growth requirements for our routes within Korea domestically and to Japan, China and other Asia Pacific regions," Jeju said in a prepared statement.

The single-aisle 737 is Boeing's best-selling passenger plane. The 737-800 version can seat up to 189 passengers.

Boeing shares rose 4 cents to $87.50 in after-hours trading. The stock fell 79 cents during the regular session.