TIMELINE: Boeing's bumpy 787 program

NEW YORK (Reuters) - Boeing (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 (73.4 billion pounds) 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.