GS Yuasa (IW 1000/929), the Japanese company that made the battery installed in an All Nippon Airways (ANA) Dreamliner that made an emergency landing said Thursday its probe could take weeks.

"It is impossible to predict at this point how long it will take, in days or weeks, because we must study the system and GS Yuasa is not the only player involved," a company spokeswoman told AFP.

The Japanese firm is taking part in a wider probe launched after aviation watchdogs in at least four countries grounded the next-generation aircraft, which has been hammered by a string of safety problems.

Regulators in Japan, India and Chile followed the lead of the US Federal Aviation Administration (FAA) in ordering an indefinite halt to all operations, after the ANA plane was forced into an emergency landing Wednesday.

Leaks and Burn Marks

Electrolyte leaks and burn marks were found on the lithium-ion battery's metal casing, ANA said. Kyodo News reported that officials from the Japan Transport Safety Board were working on the principle it overheated.

The powerful batteries used on the Dreamliner have emerged as the focus of concern in light of the ANA incident and another on a JAL flight in the United States last week, with smoke reported on both planes.

Lithium-ion batteries are widely used in consumer electronics such as laptops and mobile phones. Airlines warn passengers against carrying too many in their baggage because of the risk of overheating.

Copyright Agence France-Presse, 2013