Avolon, one of the world's biggest aircraft leasing companies, said Friday it has ordered 250 new jets from Boeing and Airbus.

The order includes 140 Boeing 737 MAX planes. From Airbus, Avolon is buying 75 jets from the A320neo family and 35 larger A330neo wide-body planes. It also has options to buy 100 more Airbus jets. These are the largest orders Avolon has ever placed with either planemaker, Reuters reported.

Avolon does not fly planes; it buys them and rents them to airlines. Leasing companies own about half of the world's airline fleet, Reuters said. They have been in high demand because airlines face long waits for new planes, and leasing also lets airlines get modern jets without paying the full price up front, Bloomberg reported.

The deal is not final yet, because China's Bohai Leasing, which owns 70% of Avolon, must get its shareholders' approval. Avolon expects that before the end of October.

Bohai's filing with the Shenzhen stock exchange gives a sense of the size: at Boeing's list prices, the 140 MAX jets are worth up to about $27 billion. Buyers like Avolon usually pay less than list price, and the planes are due to arrive by the end of 2036.

With the new orders, Avolon has 749 planes on order, on top of the 561 it owns. Its total fleet, counting planes it owns, manages and has ordered, would rise to 1,342.

"We continue to see strong demand for new-technology aircraft," said Andy Cronin, Avolon's chief executive.

In a quarterly business update, Avolon said it sold 29 planes from July to September and had deals to sell 112 more at the end of September.

The order lands as both planemakers build up huge backlogs, and Boeing is also still waiting on China. After a May summit with Chinese President Xi Jinping, President Donald Trump said China would buy 200 "big" planes, but Beijing has not released details, Bloomberg reported.

What we know: Avolon ordered 250 Boeing and Airbus jets, pending approval by its Chinese owner.
What we don't: The actual price Avolon will pay, and which Airbus models the 100 options cover.