TOKYO (REUTERS) - All Nippon Airways, which has the biggest fleet of Dreamliner jets, on Saturday cancelled another 379 flights scheduled for Feb 1-18, almost doubling the number of its cancellations since one of the planes made an emergency landing.

The latest cancellations brings the number of ANA flights stopped since the Jan 16 emergency landing in western Japan to 838. All Dreamliners have been grounded since Jan 17 due to unexplained battery problems.

ANA, which has 17 of the 50 Dreamliners that Boeing has delivered to airlines to date, said the cancellations have affected more than 82,620 passengers.

ANA said on its website that it flies around 3.7 million passengers each month on domestic and international routes.

ANA, which has put the lightweight, fuel-efficient Dreamliner at the centre of its growth strategy, may have to scale back its next 2-year plan as it considers the mounting cost of the new aircraft's grounding.

US safety officials looking into a battery fire on a separate 787 jet said on Thursday they are nowhere close to completing their probe, raising the prospect of a lengthy suspension for the technologically advanced aircraft.