The extra slots for U.S. airlines were unlocked after Japan reached an agreement with the U.S. Air Force to open up new flight paths around a nearby U.S. air base, a move needed to boost Haneda movements in the run-up to the 2020 Olympics in Tokyo.

Haneda is located closer to downtown Tokyo than the capital's other international airport Narita, and flies to more destinations throughout Japan, making it attractive for both business travelers and tourists.

United Continental Holdings Inc and Delta Air Lines Inc are each bidding for six slots while American Airlines Group Inc is bidding for four.

Thursday is the deadline for applications to the U.S. Department of Transportation.

Completion of an aviation agreement between the United States and Japan is expected later this year, United said. The new routes would launch for the 2020 summer flying schedule, once the U.S. Department of Transportation awards the slots.

United wants to fly to Haneda from its hubs at Newark Liberty, Chicago O'Hare, Washington Dulles, Los Angeles International, Houston George Bush and Guam. The flights from Newark, Los Angeles and Guam would be new routes operated by Boeing 777 and 787 models, while the flights from the other three hubs would be shifted from Narita.

Under the proposal, United said it would connect to 37 destinations in Japan from Haneda with its joint venture partner All Nippon Airways (ANA).

Industry analysts say a recent sale of Boeing 737 MAX aircraft to ANA may have weighed in the decision to grant more flying rights for U.S. airlines into Haneda, which airlines compete for aggressively due to the airport's proximity to the Japanese capital, a major center for global commerce.

Delta is proposing daily flights from Seattle, Detroit, Atlanta and Portland, Oregon, and twice-daily service between Haneda and Honolulu. American has requested a daily flight from Las Vegas and Los Angeles and twice-daily from its hub in Dallas.

Delta would fly the Airbus A330-900neo from Seattle, the A350-900 from Detroit, the A330-200 from Portland, the Boeing 777-200ER from Atlanta and the 767-300ER from Honolulu.

American, like United, would use 777 and 787 models by Boeing.

(Reporting by Tracy Rucinski; Editing by Chizu Nomiyama and Lisa Shumaker)

By Tracy Rucinski