TOKYO - Struggling Japan Airlines (JAL) was offered a $1.1-billion lifeline Thursday from partners led by American Airlines, amid a bidding war with Delta Air Lines for a piece of Asia's biggest carrier.

JAL, which last month reported its fourth straight quarterly loss, has been hovering on the brink of bankruptcy in a crisis blamed on the global aviation industry downturn, mismanagement and its huge pension obligations.

The recipient of 3 government bailouts since 2001, the airline has said it plans thousands of job cuts and a drastic reduction in routes.

It is seeking more public funds as it restructures under the supervision of a government-backed turnaround body.

American Airlines and Delta Air Lines have both sought a stake in JAL, hoping to expand their Asian operations ahead of an Open Skies agreement expected to be signed soon between Washington and Tokyo.

At a Tokyo press conference, American Airlines, the oneworld alliance -- which now groups American and JAL with 9 other major airlines -- and private equity company TPG pitched their offer.

"As part of a comprehensive restructuring American/oneworld and TPG are prepared to invest up to $1.1 billion... in JAL to bolster its financial foundation for the near and long term," they said in a statement.

"American is prepared to make a substantial commitment as part of the investment," the airline's chief financial officer Tom Horton said, without specifying what would be the airline's exact contribution.

He also said American would only seek management representation if invited.

Delta Air Lines, the world's largest carrier and a member of the SkyTeam group, last month offered JAL a $1-billion financial package.

Delta said the rescue package on the table included a $500-million equity injection, a revenue guarantee worth $300 million and $200 million in asset-backed funding.

Delta president Edward Bastian, who was also in Tokyo Thursday, said the company and its global alliance partners are ready to offer third-party additional funds to JAL, Kyodo news agency reported.

"If there was interest by the government in raising more money than that (the $1-billion package) by introducing outside, third-party investors, we would be happy to support that effort as well," he was quoted as saying.

Horton said that by accepting American's bid, JAL would gain an additional $700 million through the benefits of staying with oneworld, and because of what he said would be a greater chance of the deal passing US regulatory hurdles.

Horton said American believes that the US Department of Transportation would reject a JAL tie-up with Delta/Skyteam as anti-competitive because it would take their share of the US-Japan market to 62%.

He said currently the three global airline alliances, the other being the Star Alliance, have about one third of the US-Japan market each.

The United States and Japan are expected to sign an Open Skies agreement shortly, the Nikkei business daily reported, saying the deal could be inked in three-day talks due to start Monday in Washington.

Such an agreement gives airlines from both countries greater freedom to decide the routes and frequencies of their flights, with them aim of levelling the playing field between airlines and increasing choice for travellers.