The Chicago-based company said late Monday Luxembourg-based Cargolux Airlines International SA has ordered 10 freighter versions of the new airplane, dubbed the 747-8, with purchase rights for 10 more. Nippon Cargo Airlines of Japan has ordered eight of the freighter planes, with options for six more. Both airlines will begin receiving the planes in the latter half of 2009.

The firm orders from the two companies are worth $5 billion at list prices, although airlines typically negotiate steep discounts.

"We are thrilled to have Cargolux and Nippon Cargo choose the new 747-8 and become the launch customers for this next generation of the proud and valuable 747 airplane family," said Alan Mulally, head of Boeing's Seattle-based commercial airplanes division.

The new airplanes will use technologies and General Electric Co. engines designed for Boeing's forthcoming 787 airplane to make the 747 quieter and more efficient, Mulally said.

At a news conference in London, Mulally said the company expected to win the first orders for the passenger version next year.

"The interest for the airplane is phenomenal," Mulally said.

The new passenger version of Boeing's four-engine widebody airplane will seat 450 people, up from 416 in the most 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.

The freighter version will be about 18 feet longer than the current freighter model, the 747-400.

Both versions of the current 747 are nearly 232 feet long.

Analyst Richard Aboulafia said the 747-8 launch will likely increase pressure on rival Airbus, which is preparing for its superjumbo A380 to enter service next year. A new, slightly larger 747 could potentially reduce the market for Airbus's plane, a mammoth offering that can carry between 550 and 800 passengers in a doubledecker cabin, he said.

"It helps box the A380 into an even smaller niche," Aboulafia said.

Airbus has won 159 firm orders for the A380 so far, at a list price of $292 million each.

Boeing had been shopping a redesigned 747 around for more than a year, as it sought to garner enough interest to launch the new plane.

Without a new model, some had begun to question how long production would continue for the 747, a fabled workhorse that has been in the skies for 35 years. Boeing has recently seen business pick up somewhat for the freighter version of its current 747 model, but the company has not received an order for a passenger 747 in several years.

Aboulafia said he expects the bulk of the orders for the new 747 will also be for the freighter version, but he thinks some passenger versions to be built.

"This would remove any uncertainty about the 747 line," he said.

Shares of Boeing fell 16 cents to $66.07 in trading on the New York Stock Exchange.