* Offer to include investment from American - sources
* Deal aimed at thwarting rival offer from Delta
* Joint offer gives AA a better chance to keep JAL - analyst
* JAL shares rise over 2 percent (Adds Qantas CEO, AMR shares)
By Nathan Layne and Nobuhiro Kubo
TOKYO, Sept 18 (Reuters) - American Airlines will team up with British Airways and Qantas Airways to bolster cash-strapped Japan Airlines, two sources said, aiming to fight off a rival offer from Delta Air Lines.
The proposal, which will include a capital injection from American Airlines but may not bring money from either BA or Australia's Qantas, comes as Delta holds separate talks to invest in JAL and woo it to a rival airline alliance.
JAL, which faces its second straight loss this business year, is weighing both offers as part of a larger restructuring expected to include layoffs, route reductions and asset sales.
Both Delta and AMR Corp's American are courting JAL to gain access to promising routes in Asia, including in Japan where Tokyo's Haneda airport is undergoing a major expansion.
Speaking to Reuters in Dublin, Qantas Chief Executive Alan Joyce said it was looking at all options to keep JAL as a partner, but said it was too early to talk about investments.
"Delta made a bid for JAL and the Oneworld Alliance is actually looking at JAL as a very important partner and we're looking at all of our options," he said.
Shares of JAL rose 2.4 percent, bucking a weaker market.
Executives from JAL's Oneworld airline alliance partners American, BA and Qantas met JAL executives this week in Tokyo and told them of their plans to put together a joint offer, two people with direct knowledge of the matter said.
The American-led group will try to sell JAL on the idea that leaving Oneworld, which pools frequent flyer miles, integrates computer systems and feeds passengers between member airlines, would trigger a big loss of business for JAL.
"A tie-up with Delta would give JAL a bigger benefit when it comes to North American routes," said Ryouta Himeno, transport analyst at Mitsubishi UFJ Securities.
"But by involving other carriers which are strong in other areas, American could have a good chance to keep JAL in Oneworld and expand its reach in Asia."
Delta is in the rival SkyTeam alliance, which has no major Japanese carrier. Fellow SkyTeam member Air France-KLM has been named as a potential partner with Delta for an investment in JAL. Japan's No. 2 airline, All Nippon Airways Co, is part of Star Alliance, the third major grouping.
"Combined, the Oneworld partnership today generates over half a billion dollars for JAL in revenues on an annual basis. JAL is very aware of this number," said one of the sources, who spoke on condition of anonymity since the talks are not public.
A BA spokesman said it was attempting to persuade JAL to remain part of Oneworld rather than team up with Delta.
JAL, American and Air France-KLM have declined comment.
For a Graphic, click: http://r.reuters.com/tup66d
NEW GOVERNMENT
American Airlines has already mapped out an alliance with Oneworld partners British Airways and Iberia that would see them work together on fares, schedules and costs.
American and BA submitted an application seeking U.S. government approval in April which included other Oneworld players, and a decision was expected by October. Shares in American parent AMR pulled back 8 percent after soaring by as much as 25 percent on Thursday, when the group said it had raised $2.9 billion of finance.
In addition to an investment, American Airlines is talking with JAL about the creation of a joint venture under which the two would cooperate more closely on scheduling and revenues.
Such close cooperation requires the enactment of an "open skies" agreement under discussion between the U.S. and Japan.
The two governments finished a round of talks last week and are aiming for an agreement as early as this year.
Some Japanese officials have pushed JAL to seek a tie-up with Delta because it is larger and has more overlapping routes.
American will argue that could face regulatory hurdles as it would hand Skyteam 60 percent of the trans-Pacific market.
It will also hold out the prospect of fewer job cuts, which would play well with the labour-friendly Democratic Party which swept to power after elections last month.
JAL lost about $1 billion last quarter and has been scrambling to put together a revival plan to submit to the transport ministry, which is supervising its restructuring after the state backed a 100 billion yen ($1.1 billion) loan.
JAL is seeking another 250 billion yen through a mixture of equity and debt. Bankers say this will almost certainly need to include the state, through loan guarantees or a capital boost. (Additional reporting by Daryl Loo, Andras Gergely, John Bowker, Tim Hepher, Editing by Lincoln Feast, Rupert Winchester)