Speaking to some 2,000 employees gathered for a celebration at the assembly plant in this city north of Seattle, Joe Sutter noted that the current version of the plane, the 747-400, has been the hottest seller of any 747 model yet.

The company has sold more than 700 of them since 1985, according to its online database of orders and deliveries.

"I predict the 747-8 will match that market and might even surprise the marketeers," said Sutter, who retired in 1986 after 40 years at Boeing and now works as a consultant to the company.

Boeing announced last month that it was launching the 747-8, a bigger, more fuel-efficient version of the four-engine widebody plane. It's designed to compete with rival Airbus SAS' A380 superjumbo, which will overtake the 747 as the world's largest commercial jet when it enters service next year.

So far, Boeing has won orders only for the freighter version of the 747-8, which will be about 18 feet longer than the current freighter model.

The passenger version will seat 450 people in a standard three-class configuration, up from 416 in the current model, and will feature a redesigned interior. It will be nearly 12 feet longer than the current 747, and will be capable of flying 9,200 miles.

Both versions of the current 747 are nearly 232 feet long. The A380 is about 240 feet long and will carry about 550 passengers in three classes or 800 passengers in a single class. It, too, will be capable of flying about 9,200 miles.

Jeff Peace, vice president and general manager of the 747 program, said Boeing has marketed the 747-8 to several interested airlines and expects an order for a passenger version of the plane sometime next year.

Sutter, 84, recalled the early days of the 747 program, when his wife would dread going to the grocery or playing bridge with her friends, because people would ask her what her husband was thinking, designing such an enormous plane.

"The question, 'Will this thing ever fly?' was actually asked," Sutter said, drawing chuckles from the crowd. "The market people in New York thought it might be a white elephant, and people were predicting that 200 of these airplanes would be the maximum market. ... Those 200 airplanes have now stretched out to 1,400 airplanes, and all of the airplanes that were being developed at the same time as the 747 have disappeared."

Industry analysts have predicted that the 747-8 will steal potential A380 customers away from Airbus, based in Toulouse, France, and owned mostly by European Aeronautic Defense & Space Co.

In a recent interview, Airbus spokesman Clay McConnell said the company remains confident that it will win at least half of the market's jumbo jet orders over the next 20 years.

"This is the sixth derivative of the 747. It's a plane that can be offered out there at a relatively low cost - smart and entirely predictable move on their part. We still think we have a better product," McConnell said.

Kourosh Hadi, a chief product development engineer, said designs for the 747-8 will be finalized by 2007. Boeing will begin building the plane in 2008, run the first test flight in early 2009 and deliver the first plane in September of that year.