Japan Airlines Corp's <9205.T> board voted to file for bankruptcy protection on Tuesday, media reported, a move that will see it slash 15,000 jobs and replace aging planes to survive an industry beset by volatile fuel costs and fickle flyers.

All board members also voted to resign, Jiji News Agency and other media said. JAL officials were not immediately available for comment.

Sources have said JAL, Asia's largest airline by revenues, will remain in the skies under a state-backed restructuring plan but cut unprofitable routes, non-core businesses and pension payouts and as it tries to free itself from about $16 billion in debt.

JAL, which has been bailed out by the Japanese government three times in the past 10 years, must now look to reinvent itself through painful operational cuts and tough decisions about foreign capital and alliances.

I am not worried about the future of the carrier as I believe the government will strongly support it, said Yasuhiro Matsumoto, credit analyst at Shinsei Securities.

But whether it will be able to grow as a business is unclear. I can't see how JAL is going to build its network domestically and internationally.

The airline is expected to file for bankruptcy around 0800-0830 GMT (3-3:30 a.m. EST), two sources familiar with the matter said. Japan's Transport Minister Seiji Maehara will hold a news conference at 0845 GMT, the ministry said.

The move could make rival All Nippon Airways Co <9202.T> Japan's new flagship carrier, according to some analysts. Shares in ANA fell 4.2 percent after rallying to a six-month high last week.

Shares of JAL closed flat at 5 yen after trading down 2 yen to 3 yen. The airline has lost more than 90 percent of its market capitalization since the start of the month.

With a market value of about $150 million, JAL is now smaller than minor carriers Croatia Airlines and Jazeera Airways and is worth less than a Boeing 747.

I thought that there was no way that JAL would fail, said Akiko Saito, a 63-year-old retiree waiting for a flight at Tokyo's Haneda Airport. Even when the value of my JAL shares fell from 800,000 yen to below 120,000 yen, I was convinced that it would recover, and I held on to my stock.

JAL bonds maturing in 2013 were priced at the equivalent of just 27.8 cents on the dollar, versus around 70 cents last month, but traders said that trade dried up on the bonds on Tuesday.

DEBT-LADEN

The tough love for JAL by Prime Minister Yukio Hatoyama's four-month-old Democratic Party-led government signals a shift from previous governments under the long-dominant Liberal Democratic Party, which had authored the previous JAL bailouts.

JAL was saddled with 1.5 trillion yen ($16.6 billion) in total liabilities as of the end of September. That level of debt would make it the sixth-largest bankruptcy in Japan's history, ranking just below the 2001 collapse of retailer Mycal.

Following similar bankruptcies by overseas airlines such as Delta Air Lines and United Airlines , JAL plans to cut about a third of its 47,000 workforce and erase about two dozen unprofitable routes, sources said.

JAL is expected to file for protection from creditors using a procedure that will allow it to continue operations and seek to rebuild itself, similar to Chapter 11 in the United States.

In return, the state-backed Enterprise Turnaround Initiative Corp of Japan (ETIC) will support the carrier with about 300 billion yen in capital and creditors will be asked to forgive about 350 billion yen of loans, sources said.

Bankruptcy will only be the beginning for an airline with depleted capital, facing headwinds such as rising fuel prices and shrinking passenger numbers, on top of hefty restructuring costs.

Fuel hedging contracts may also be affected by a bankruptcy filing. JAL uses mostly in Brent forward contracts and about 40 billion yen is estimated to be exposed in the event of an automatic termination, a source familiar with the matter said.

JAL needs to do what it has long put off: Focus on its main business and cut operations it doesn't need, said Andrew Miller, chief executive officer of CAPA Consulting.

I would have a fire sale -- get rid of the family silver, sell everything that is non-core and focus in on the core and make that work efficiently, he said.

ALLIANCE IN QUESTION

JAL will also need to make a decision about competing aid offers from Oneworld alliance partner American Airlines and rival Delta, which wants to woo JAL to its SkyTeam group.

The carrier has spent two decades trying to recover public trust following a 1985 crash that became the world's worst single aircraft disaster in history, claiming 520 lives.

Kazuo Inamori, the 77-year-old founder of electronics maker Kyocera Corp <6971.T>, was tapped last week to become JAL's new chief executive officer to oversee its restructuring.

JAL's restructuring plan also calls for increasing the fuel efficiency of its fleet, replacing 53 bigger jets with 33 small jets and 17 regional ones.

I think a revival of JAL will be good for manufacturers such as Mitsubishi Heavy industries <7011.T> which is developing new regional jets, said Shinsei's Matsumoto.

($1=90.43 Yen)

(Additional reporting by Nathan Layne, Nobuhiro Kubo, Chris Meyers and Linda Sieg; Editing by Lincoln Feast and David Dolan)