EVERETT, Wash. — Boeing Co. unveiled its first fully assembled 787 yesterday to an audience of thousands who packed into its wide-body assembly plant for the plane's extravagantly orchestrated premiere.

With flight attendants on stage from each airline that has ordered the jet, the giant factory doors opened wide as the plane slowly moved into view to the strains of a theme song composed specially for the 787, which Boeing calls the Dreamliner.

"Our journey began some six years ago when we knew we were on the cusp of delivering valuable new technologies that would make an economic difference to our airline customers," Mike Bair, vice president and general manager of the 787 program, told the crowd."In our business, that happens every 15 years or so, so you've got to get it right."

Boeing Chief Executive Jim McNerney said the 787 will bring about a "dramatic improvement in air travel: to make it more affordable, comfortable and convenient for passengers, more efficient and profitable for airlines, and more environmentally progressive for our Earth."

Boeing has won more than 600 orders from customers eager to hold the jet maker to its promise that the midsize, long-haul jet will burn less fuel, be cheaper to maintain and offer more passenger comforts than comparable planes flying today.

The 787, Boeing's first all-new jet since airlines started flying the 777 in 1995, will be the world's first large commercial airplane made mostly of carbon-fiber composites, which are lighter, more durable and less prone to corrosion than aluminum.

To date, Boeing has won 677 orders for the 787, selling out delivery positions through 2015, two years after Airbus SAS expects to roll out its competing A350 XWB.

In a rare tip of the hat to the competition, Airbus congratulated Boeing on the 787, whose commercial success has chipped away at the edge the European plane maker once held over its Chicago-based rival.

"Even if tomorrow Airbus will get back to the business of competing vigorously, today is Boeing's day — a day to celebrate the 787," Airbus co-CEO Louis Gallois said in a letter to Boeing Chairman and CEO James McNerney.

"Today is a great day in aviation history. Whenever such a milestone is reached in our industry, it is always a reflection of hard work by dedicated people inspired by the wonder of flight," the letter said.

Airbus customers forced it to redesign the A350, which pushed back production. Airbus also has faced problems with its A380 superjumbo, which has been hit with delays that slashed profit projections for Airbus' parent company, European Aeronautic Defence & Space Co.

Boeing hired former NBC "Nightly News" anchor Tom Brokaw to serve as master of ceremonies for the 787 premiere, which was broadcast live on the Internet and on satellite television in nine languages to more than 45 countries. The company rolled out red carpet and set out roughly 15,000 seats for spectators at one end of the 787 factory north of Seattle.

The company invited thousands of its employees and retirees to watch via satellite at the stadium where the NFL's Seattle Seahawks play, and it hosted viewing parties for 787 customers and suppliers in dozens of other locations around the globe.

Final assembly of the first 787 started in late May, after a gigantic, specially outfitted superfreighter started flying wings, fuselage sections and other major parts to Boeing's wide-body plant.

Once production hits full speed, the company expects each plane to spend just three days in final assembly, but this time, Boeing workers spent several weeks installing electrical wiring and other innards that suppliers will eventually stuff into their sections of the plane before they're delivered to the assembly plant.

Boeing decided to handle that work in-house for the first few planes rather than risk any production delays.

Despite a few snags the company says it anticipated — including an industrywide shortage of fasteners brought on by a surge in demand for new jets in recent years — Boeing officials say nothing so far has threatened to bump the 787 behind schedule.

The first test flight is expected to take place between late August and late September. The plane is set to enter commercial service next May after Japan's All Nippon Airways receives the first of 50 Dreamliners ordered.

The 787 unveiled yesterday is the first of six flight-test airplanes, while two other planes will be used for static and fatigue tests. The ninth plane off the assembly line will be the first one delivered to All Nippon.

The 787-8, the first of three 787 models Boeing has committed to making, has an average list price of $162 million.