Dubai International Capital (DIC) has bought 3.12% of European Aeronautic, Defence and Space (EADS).
DIC owns Emirates, which is the biggest customer for the A380
The government of Dubai owns DIC along with Emirates, the airline that is the largest customer for the Airbus A380.
The price has not been announced, but at Wednesday's closing price, it would have cost 614m euros ($836m; £415m).
It is a big vote of confidence in the restructuring plan for Airbus, which will include 10,000 job cuts and the sale of up to six factories.
DIC said it would not try to take any role in running EADS and would not be seeking a seat on its board.
Profits at EADS fell 94% last year, hit by delays to the A380 super-jumbo, industrial problems and the weak dollar.