INTERVIEW-Branson:unlikely all big US airlines will survive

* Virgin's Branson says at least two US airlines vulnerable

* Virgin interested in launching Tokyo-Sydney service

TOKYO, June 2 - British entrepreneur Richard Branson, founder and president of Virgin Atlantic Airways, said at least one major U.S. airline could fail by the end of next year.

"I just happen to believe it is unlikely that all the big American carriers will survive the next 12 to 18 months," he told Reuters in an interview in Tokyo on Tuesday.

Branson did not specify which airlines he was referring to.

Analysts have been saying that U.S. airlines, hit hard as the recession puts a crimp on travel demand, face a potential liquidity crisis if revenues keep falling while credit markets remain tight.

"There are these two big American carriers that are vulnerable. If one of them goes bankrupt the other will survive. Anybody in the airline industry knows which are the most vulnerable," Branson said.

Branson, visiting Tokyo to celebrate Virgin's 20 years of flying to the city, expressed scepticism about whether Washington would help the airlines as it has done with the auto sector.

"I don't think that the American government will yet again put more billions into the airline industry. They've learned their lessons with the car industry," he said.

Virgin Atlantic said last week that its yearly profits nearly doubled, but warned that the weak economic environment would make it "almost impossible" for airlines to make a profit in the current year.

Branson also said Virgin, which earlier in the day announced a code-share deal with All Nippon Airways (ANA), is interested in launching flights between Australia and Tokyo's Haneda Airport, which is undergoing a major expansion, in the next 12 to 18 months.

Virgin launched in February V Australia airlines, which flies between Sydney and Los Angeles, and Brisbane and Melbourne to Los Angeles. It also plans to launch services between Sydney and Johannesburg, Branson said.

"I think it's also good to start flying from Japan to Sydney so if we were to do that, I think some sort of relation with ANA would make sense," he said.