By Dan Catchpole

SEATTLE, Oct 14 (Reuters) - Boeing BA.N delivered 55 jets in September, up from 33 a year earlier when a strike by 33,000 factory workers in the Northwest curtailed production, the planemaker said on Tuesday.

The total, broadly steady from August's 57 deliveries , marked Boeing's strongest September since 2018, when it handed over 87 jets but it still lagged rival Airbus AIR.PA, which delivered 73 aircraft last month.

For the first nine months of the year, Boeing delivered 440 airplanes to Airbus' 507 jets.

The U.S. planemaker handed over 40 of its 737 MAX jets last month, including 10 to Ryanair RYA.I, one of which marked Boeing's 2,000th MAX delivery.

It also delivered one 737 NG for conversion into a P-8 patrol aircraft for the U.S. Navy and 14 widebodies, comprising four 767s, three 777 freighters, and seven 787s. Eight aircraft went to Chinese customers, including a 777 freighter, a 787, and six 737 MAX jets.

U.S. President Donald Trump threatened to impose export controls on spare parts for Boeing airplanes on Friday.

However, tensions had cooled by Monday after a weekend of substantial communications between Washington and Beijing, according to U.S. Treasury Secretary Scott Bessent.

Boeing booked 96 new orders in September, including 30 737 MAX for Norwegian Airlines and 50 787s for Turkish Airlines. Uzbekistan Airways also ordered 14 787s. It also booked two 737 MAX orders for an unidentified customer, the company said.

Enter Air canceled one 737 MAX order, resulting in 95 net orders after cancellations and conversions.

After accounting for adjustments, the company's backlog decreased slightly from 5,994 aircraft to 5,987.

(Reporting by Dan Catchpole in Seattle, Editing by Nivedita Bhattacharjee)

((dan.catchpole@thomsonreuters.com; 651-231-1623))