Boeing is reassessing the schedule for the new 787, the company said, an aircraft that some analysts believe will be further delayed.
Shares of Boeing , a component of the Dow Jones Industrial Average, were down about 3.5 percent Friday.
When the company announced in January that the 787 would be delayed, another review of the scheduled release of the widebody jet was begun, spokeswoman Yvonne Leach said.
Boeing's goal is to power up the plane in early April and send it on its first flight by the end of June, Leach said.
Boeing's 787 program has been hit by a series of delays caused largely by work that had to be done on the final assembly line after it was not handled at supplier factories as planned.
Originally, Boeing said it would begin test-flying the 787 in August or September of last year and that it would deliver the plane to All Nippon Airways in May. Now the company is trying to deliver the plane to customers in early 2009.
Boeing has received around 850 orders for the plane from more than 50 customers.