UPDATE 1-Spirit Aero's profit nearly doubles as aircraft makers raise output

* First-quarter revenue rises 20 pct

* Earnings $1.07/share vs $0.57 a year earlier

(Adds details, background, share price)

May 2 (Reuters) - Aircraft component maker Spirit AeroSystems Holdings Inc's quarterly profit nearly doubled, partly helped by strong demand for large commercial aircraft.

Spirit, which makes fuselages, wings and propulsion systems for aircraft, has been able to increase revenue as aircraft makers ramp up production.

Boeing Co and Airbus Group NV expect aircraft demand to reach over $4 trillion over the next 20 years and have raised their production rate. (http://r.reuters.com/zag98v)

Boeing is currently producing 42 of its 737 jetliners every month, up from 38 in October, and expects to raise that to 47 by 2017. (http://r.reuters.com/ceg98v)

Spirit provides aerostructures for the 737 jets. It also supplies components to Airbus.

The company's net income rose to $153.6 million, or $1.07 per share, in the first quarter ended April 3, from $81.2 million, or 57 cents per share, a year earlier.

Revenue rose 20 percent to $1.73 billion.

The company's shares closed at $30.43 on the New York Stock Exchange on Thursday. They have gained about 50 percent in the last year, compared with a 41 percent rise in the Dow Jones U.S. Aerospace and Defense index.

(Reporting by Sagarika Jaisinghani in Bangalore; Editing by Joyjeet Das)