Boeing to improve current 777 jet, weighs up middle of market

Unveiling details and timing at a gathering of aviation financiers, marketing vice-president Randy Tinseth said Boeing was confident it could "work through a successful transition".

The improved efficiency will be due in part to aerodynamic improvements, which will reduce fuel burn by 1.2 percent, and 1,200 pounds lower weight, Tinseth told the Istat conference.

The changes appear designed to try to avoid cutting production while waiting for the new model, as Airbus has been forced to do with its smaller A330 wide-body jet.

Tinseth also gave a new glimpse of Boeing's research into a possible new mid-market product in a niche between its narrow-body and wide-body jets, saying customers had expressed interest in a jet bigger than a 757 and with 20 percent more range. It has already ruled out reviving the out-of-production 757 itself.

(Reporting by Tim Hepher, editing by David Evans)