Boeing delivered fewer jets in 2003 than European rival Airbus, the first year this has happened.
Boeing is pinning its hopes on the 7E7 jet
The American company delivered 281 jets in 2003, and Airbus sent its 300th plane, to Singapore Airlines, just before Christmas.
Official figures from Airbus, 80% owned by EADS and 20% by BAE Systems, are due on 15 January.
Shares in Boeing, the world's largest aerospace company, closed down 14 cents at $41.93 on New York's Stock Exchange.
Airbus is expected to come in slightly above the 300 figure for the full year.
Boeing had projected 280 deliveries in 2003 after delivering about a hundred more in 2002. This year's result is the lowest level since the 271 in 1996.
Airbus, based in France, has been aggressive in marketing its line of aeroplanes and has been making steady inroads against Boeing, the only other manufacturer of large commercial jets.
In December EADS signed a deal to sell six Airbus A380 super-jumbo planes to Malaysia Airlines for $1.6bn.
In the same month Boeing said it was to start taking orders for its new 7E7 Dreamliner passenger jet.
The 200-300 seat aircraft is Boeing's first new commercial airliner for more than a decade.
The new model, which is not expected to enter service until 2008, is seen as vital for Boeing's future.
Boeing was rocked last year when chief executive Phil Condit resigned in the wake of a number of scandals and performance problems in Boeing's military contracting business.
And chief financial officer Michael Sears quit in November 2003 for unethical conduct.
Boeing on Tuesday named James Bell as chief financial
officer on a permanent basis to replace Sears. Mr Bell, 55, had
been acting as CFO since Sears' dismissal.