Chinese airlines and leasing companies have told Boeing they want to buy some 200 of Boeing's newest jets, the 737 Max, pending government approval.
That news was reported Friday by Reuters News which said two unnamed sources had confirmed the pending purchases.
Depending on the models involved, the deal would be worth some $21 billion at list prices.
The 737 Max is the latest version of the world's best selling airliner. The plane will be equipped with new engines, aerodynamic improvements and other enhancements that will improve the plane's fuel efficiency and reliability.
The first of the the new planes is scheduled to enter service in 2017. They will be built at Boeing's Renton plant.
The news of possible Chinese sales of the new planes came during a week when Boeing itself and its airline customers announced several other deals.
Korean Airlines finalized a deal for 12 Boeing jetliners this week including five 747-8 Intercontinentals, five 777-300ERs and a single 787 Dreamliner. At list prices, those planes are worth $3.9 billion, Discounts are common.
Korean is one of less than a handful of airlines that has committed to flying the passenger version of the original jumbo jet. The 747-8 succeeds the 747-400. It is equipped with new engines, a new wing and an upgraded interior. The plane has been stretched to carry up to 465 passengers in a mixed-class configuration.
The four-engine aircraft has been a slow seller because of the rise of twin-engine planes like Boeing's own 777 in international service.
Boeing announced early last week that it was cutting the production rate for the 747 to 1.5 planes a month from 1.75 aircraft a month.
Boeing believes that the plane will continue to enjoy a market as a freighter because it has no direct competition in that field.
The aircraft manufacturer also announced an order for two 737-900ER aircraft from Israel's El Al Airlines. The order followed by two weeks the delivery of the first of a prior order of 737-900ERs to the airline.
Aerolineas Argentinas earlier this week also signed an order for 20 737-800s worth $1.8 billion.
Through Tuesday, Boeing had recorded 942 net orders for 2013 so far, making this year, with more than two months to go, one of the aircraft company's better order years.
Net orders for the 737 amount to 775 this year. Airlines and leasing companies have also ordered 131 787 Dreamliners and 36 777s in 2013. Those totals don't include the Korea Airlines orders.