Airbus stayed well ahead of Boeing in August, based on the success of its revamped A320 family of narrow-body jets.
The European plane maker said in a monthly tally it had sold 1,156 aircraft between January and August.
Cancellations brought the net total of planes sold in the first eight months down to 1,015.
Boeing sold 472 aircraft or a net total of 370 between January and August.
In an attempt to challenge Airbus's revamped A320neo family, Boeing said on August 30 it planned to roll out a more efficient version of its best-selling 737 narrow-body with a new engine in 2017.
The new model, named the 737 MAX, will compete with the revamped A320neo family, a similar model due to be equipped with fuel-saving engines and delivered in 2015.
Boeing cited order commitments, which will need to be confirmed as firm orders at a later stage, for 496 of the new planes from five airlines.