State-run China Aviation Supplies, which leases planes to Chinese airlines, said the order was for 260 B-737s as well as 40 B777s and B787s.
Analysts said, however, that some of the order may be among the more than 300 from undisclosed buyers posted this year and that it was not yet understood how much of the China deal would be entirely new business.
Boeing had 334 orders by unidentified customers as of Oct. 24, of which 290 were for its 737 narrow body family.
Representatives for Boeing did not immediately respond to requests for comment on whether the planes were new or existing orders.
Aircraft orders are also announced at list prices but buyers usually get discounts.
China Aviation Supplies has also played a prominent role in deals announced during previous government exchanges.
Boeing's latest signing in China follows an order for 39 wide-body jets from Singapore Airlines last month.
Earlier on Thursday, aircraft engine marker General Electric said it had signed deals worth $3.5 billion in China, including an agreement with Juneyao Airlines Co Ltd and ICBC Leasing, the leasing arm of state bank Industrial and Commercial Bank of China Ltd.
(Reporting by Brenda Goh in SHANGHAI, Ben Blanchard and Stella Qiu in BEIJING; Additional reporting by Jamie Freed in SINGAPORE; Editing by Richard Borsuk and Edwina Gibbs)
(This story has not been edited by NDTV staff and is auto-generated from a syndicated feed.)