LOS ANGELES, Aug. 22 (Xinhua) -- Aircraft maker Boeing has asked the Pentagon to allow six months for a new bid to build U.S. Air Force's next generation of aerial-refueling tanker, or the company will decide not to bid for the 40-billion-dollar project.

    A Boeing spokesman on Friday confirmed comments made by Boeing defense unit chief Jim Albaugh, who earlier told the Wall Street Journal that the company might not make a new bid for the contract if not given enough time.

    Boeing has concluded that the Pentagon wants an aircraft that can haul more fuel than the 767-200 variant that the company first proposed, and said working up a new bid would take longer than the time the Pentagon requires.

    U.S. Defense Department officials say they want to make a decision on the contract by early next year, and are considering giving Boeing and its rival Northrop Grumman a total of 60 days to submit new bids.

    A joint venture between the Los Angeles-based Northrop and its partner European Aerospace Defense and Space Co., which is the parent company of Airbus, won the original tanker project earlier this year, but the Pentagon decided to rebid the contract after Boeing protest against the bidding process.

    The Pentagon presented a preliminary request for proposals last month and is scheduled to release final specifications for the project next week.