May 1 (Reuters) - The head of the world's largest

airplane lessor dismissed the prospect that Brazil's Embraer ( ERJ )

would challenge the planemaking duopoly of Airbus and

Boeing ( BA ) any time soon, after the Wall Street Journal reported it

was exploring a new jet.

"I doubt we'll see anything in material numbers before the

end of the 2030s. It's just impossible to develop a new

aircraft, particularly if you need a new engine technology, you

would have to be well down the track already to have that

delivering this side of 2030. So that's not happening," AerCap ( AER )

Chief Executive Aengus Kelly told analysts.