WASHINGTON, April 3 (Reuters) - The U.S. Federal

Aviation Administration said on Thursday it would launch an

investigation after the crew on a United Airlines Boeing

737 flight from Key West, Florida to Newark, New Jersey,

reported a fire in the cabin.

The airplane diverted and landed safely at Washington's

Dulles airport around 4:45 p.m. ET (2045 GMT) on Thursday, the

FAA said in a statement. United said the diversion was prompted

by light smoke venting from a galley oven.

All passengers deplaned normally at the gate and the airline

arranged for a different aircraft to take passengers to Newark

on Thursday evening, United added. The plane had 98 passengers

and five crew on board.