SYDNEY, Australia — Nearly a decade in the making and two years late, the world's largest passenger jet made its commercial debut Thursday with a flight from Singapore to Sydney that carried more than 400 people, some sipping free Dom Perignon champagne.

SYDNEY, Australia — Nearly a decade in the making and two years late, the world's largest passenger jet made its commercial debut Thursday with a flight from Singapore to Sydney that carried more than 400 people, some sipping free Dom Perignon champagne.

The A380, which if equipped just with coach seats, could transport an unprecedented 850 passengers. Some passengers paid handsomely to make history on Singapore Airlines Flight 380. The carrier auctioned tickets on eBay, with proceeds going to charities in Australia and Singapore, and a Sydney businessman bid $100,380 for two spaces in one of 12 luxury suites.

The plane was configured for 399 people in economy and 60 in business class. Of the 468 passengers, 75 were newspaper and television reporters. "I expected it to have a party atmosphere, but I didn't expect all the media. It's become a media circus," said Dean Wood, a Miami resident who paid $15,000 for business-class seats for himself and his wife, Stephanie Mogol-Wood. The couple estimated they were interviewed 20 times.

Passengers snapped pictures of one another in various areas of the plane, including the spiral staircase in the rear, and in the 15 bathrooms, some capacious enough for several people to squeeze in at one time.

"It's like a freak show," said Anthony MacKay, an Australian living in London who paid $12,500 for two business-class tickets.

Last week, when Singapore Airlines Chief Executive Chew Choon Seng took delivery of the A380, for which the carrier paid $300 million, he called it "the new queen of the skies." But whether the A380 will redefine air travel the way 747 did won't be known for a while.

To date, Boeing has sold more than 1,500 of its 747s, and its is the most profitable large plane ever built.

At this point in the Megaliner vs. Dreamliner race, Boeing is ahead. It has sold more than 700 Dreamliners — the first 787 will go into commercial service late next year — while Airbus has orders for 165 Megaliners.

Airbus officials said they were expecting a second wave of orders with the start of regular commercial flights. If the A380 performs well for the airlines, "it has a chance," said Adam Pilarski, senior vice president of the aviation research company Avitas Inc. "It's a big plane, but how many people are on a cruise ship? Not many people complain about that."

Problems assembling the A380 drove up the development cost from an initial $12 billion estimate to nearly $20 billion. That led to a major shake-up at Airbus that included the ouster of several top executives.

Boeing's 787 Dreamliner hasn't been immune to problems. In an embarrassing setback, Boeing said earlier this month that shortage of parts would delay the first delivery by six months.

For Singapore Airlines, the decision to fly the A380 on the Singapore-Sydney route was strategic. The airline has been in a battle with British Airways and Qantas to fly the lucrative route that connects travelers from Europe and Australia. Before jets, propeller planes from Europe had to make numerous stopovers to reach Australia. Because of the "hops" involved, the trip became known as the Kangaroo Route.

These days, a flight from London typically stops over in Singapore before proceeding to Australia, and vice versa. Singapore Airlines hope the introduction of the A380 will help it lure passengers, particularly first- and business-class customers.

The test will come Sunday, when the Megaliner begins regularly scheduled service, requiring it to land, unload passengers, clean the cabin, restock meals, refuel, reload passengers and then take off within 110 minutes on a daily basis.