Boeing, the US aircraft manufacturer, has stuck by its plans to speed up production of its 787 Dreamliner planes and has seen no reason to drop the troubled lithium-ion batteries at the centre of the passenger jet's problems, according to CEO Jim McNerney.

The announcement on Wednesday came after a fire and emergency landing earlier this month, both involving the batteries, prompted regulators to ground Boeing's newest and highest-profile plane.

Japan's All Nippon Airways said on Wednesday that it had replaced the batteries 10 times before the overheating problems surfaced.

CEO McNerney said the airline had been replacing 787 batteries for maintenance reasons, rather than safety concerns at a "slightly higher" rate than Boeing's expectations.

The company said an estimated 2,000 batteries of various types are replaced annually on its range of planes.

US aviation officials say they have requested that Boeing provide a full operational backlog of the batteries on the 787s.

McNerney said his company has made "good progress" in determining the cause of the problems although he did not provide a timeline for when the plane would return to the skies.

The 787 Dreamliner, valued at $200 million each, costs more to build than Boeing's selling price.

Deliveries are vital to Boeing's cash flow, since it collects up to 60 percent of its purchase price at the time of dispatch.

Despite the Dreamliner currently making a loss, Boeing projects that it will eventually break even.

Source: Agencies