US aerospace company Boeing has won a contract from the UAE Air Force for six C-17 aircraft.
The UAE is the second country in the Middle East to order the large transport aircraft after Qatar. The financial terms of the deal have not been disclosed.
Under the agreement, the UAE will take delivery of the four planes in 2011 and a further two in 2012.
The planes can carry large combat equipment and troops, or humanitarian aid over large distances.
The UAE announced in 2009 that it planned to modernise airlift capabilities by buying the C-17 aircraft.