TIMELINE: Boeing's bumpy 787 program

NEW YORK (Reuters) - Boeing Co (BA.N) announced the third major delay on its 787 Dreamliner on Wednesday, putting the revolutionary, carbon composite aircraft about 15 months behind its original schedule.

The fuel-efficient plane is the most successful launch in Boeing's history, racking up 892 orders in four years, worth more than $145 billion at list prices.

But repeated delays, caused by late redesigns, underperforming suppliers and a shortage of key parts means the plane has not yet left the ground and threatens to seriously damage Boeing's finances and reputation.

The following events show the mixed progress of the 787 program.

2002 - Boeing drops its "Sonic Cruiser" concept, responding to airlines' calls for better fuel efficiency rather than extra speed.

June 2003 - The company dubs its new, carbon-composite airplane the "Dreamliner."

Dec 2003 - Boeing approves an initial version of the plane, with the temporary name 7E7, the E standing for "efficiency."

April 2004 - It officially launches the plane as Japan's All Nippon Airways (9202.T) (ANA) orders 50.

Dec 2004 - The company ends 2004 with 56 orders for the new plane, fewer than it had expected.

Jan 2005 - Boeing gives the plane the official designation 787.

Dec 2005 - It ends 2005 with 232 orders for 787s, for a running total of 288.

July 2006 - Popularity of the 787 design forces EADS (EAD.PA) unit Airbus to go back to the drawing board on its competing A350, relaunching it as the A350 XWB (extra wide body).

Dec 2006 - Boeing ends 2006 with 160 orders for 787s, for a running total of 448.

Jan 2007 - Unconfirmed talk that some 787 suppliers are falling behind schedule sends Boeing shares lower. Boeing CEO Jim McNerney says the plane is on target for its first test flight around end of August 2007 and first delivery May 2008.

May 2007 - Boeing starts to put together the first 787 in Everett, Washington.

June 2007 - Reports surface at the Paris Air Show that 787 is up to four months late. Boeing says the first test flight may slip to September 2007, while still on schedule for first delivery in May 2008.