A proposal acceptance is a part of the purchasing process which often comes before an agreement to buy.

At a briefing in London, Boeing Commercial Airplanes' vice president of marketing Randy Baseler declined to say whether any of the customers would likely confirm these orders at next week's Farnborough Air Show.

He said he remained very confident about the company's ability to secure further orders from a total of 30 proposals outstanding, covering an additional 400 aircraft.

The mid-sized 7E7 Dreamliner, seating around 250 in a typical seating formation, is due to enter into service beginning in 2008.

Boeing says the plane will use 20 percent less fuel than existing, similar-sized aircraft through more efficient engines and the increased use of lightweight composite materials in the plane's structure.

Last week, Boeing confirmed agreements covering 10 of the planes from First Choice Airlines - part of British-based First Choice Holidays PLC - and Italy's Blue Panorama.

Boeing had previously received proposal acceptances for the fuel efficient aircraft from Japan's All Nippon Airways Co. Ltd. and Air New Zealand covering 52 aircraft, but now says it has received the additional eight proposal acceptances from as yet unnamed airlines.

Earlier Wednesday, British Airways PLC chief executive Rod Eddington said he was interested in both the 7E7 and Airbus' super jumbo A380, but was "not about to order either of them."

He was speaking at the launch of the airline's 2003-4 Social and Environmental Report, which showed that carbon dioxide emissions from BA's fleet rose compared with the previous year due to an increase in flight volumes.

Shares of Boeing closed Wednesday down 94 cents, or 2 percent, at $49.32 on the New York Stock Exchange.