Airbus' military A400M airlifter is to delay deliveries by at least six months with a "risk of a further slippage of up to a half year", according to an EADS statement.
Deliveries were originally scheduled to start in October 2009. The delays will affect A400M deliveries to both European and other customer nations.
The statement said: "A400M deliveries are now expected to start six months later than initially planned with a risk of a further slippage of up to a half year."
EADS cited causes including "slow progress in engine development, which stands on the critical path to achieving first flight, schedule overruns in the systems development, and a flight test programme that differs significantly from that of commercial Airbus aircraft."