American Airlines Inc. President and CEO Gerard Arpey said Wednesday that Japan Airlines Corp. should remain in their alliance instead of teaming up with Delta Air Lines Inc., adding his group may invest in JAL more than the already proposed $1.1 billion.

"We have offered JAL a total value proposition that is superior in every way to the alternative," Arpey told a news conference in Tokyo. He said the proposal is better and more realistic.

American Airlines and other members of the oneworld group, as well as private-equity fund TPG Inc., are jointly offering a $1.1 billion investment in JAL, while Delta and other members of Sky Team alliance are offering a $1.02 billion financial package, including an investment of $500 million.