Boeing announced on Wednesday a record order by a group of Chinese firms for the purchase of 300 aircraft worth some $38 billion.

The order, announced to coincide with President Xi Jinping's visit to a Boeing plant near Seattle, comprises 240 planes for Chinese airlines and 60 aircraft destined for leasing companies, Boeing said in a news release.

The deal sets a new record for the aircraft industry, surpassing an order finalized in 2015 by Indian airline IndiGo for 250 Airbus planes worth some $26.5 billion.

Boeing said 190 of the planes are the narrow-bodied 737 model, while the other 50 are wide-body planes. The leasing firms ICBC and CDB Leasing will acquire 60 of Boeing 737 aircraft under the deal.

The order was placed on behalf of the Chinese carriers and leasing companies by the China Aviation Supplies Holding Company (CASC).

"China is a critical international market for commercial airplanes," said Boeing commercial aviation chief Ray Conner.

"We thank Chinese customers for selecting fuel-efficient Boeing airplanes to meet their fleet growth and expansion."

China has accounted for about one in four of Boeing's 2015 deliveries, Conner said in a message to employees seen by AFP.

The US aerospace giant is sparring with Airbus for preeminence in the giant market.

The final value of Wednesday's agreement could be lower than $38 billion depending on whether there are rebates offered in final talks.