Delta Air Lines is ending three routes to Tokyo's Narita International Airport, the first sign that its Japanese hub, built by Northwest Airlines, may be unspooling as a result of changes to aviation rules.

The carrier predicted in February that it could lose many Narita routes if the U.S. signed an agreement with Japan to gradually open up more U.S. flights to the Tokyo's closer-in Haneda Airport. This week, Delta announced the first of such route losses since that agreement took effect while also signaling a shift in its Asia model away from a megahub toward more direct, point-to-point flights.

Delta said it will stop flying between Narita and New York's John F. Kennedy International Airport this fall. It will also abandon Narita-Osaka and Narita-Bangkok routes.

Meanwhile, the Atlanta-based airline is waiting for the U.S. Transportation Department to give it final approval for two new daytime routes — one from Minneapolis-St. Paul and the other from Los Angeles — to Tokyo's smaller but more convenient airport, Haneda.

Delta executives will decide whether to cancel the existing MSP-to-Narita flight if and when the government gives a final approval to the MSP-to-Haneda route. The airline is scrambling to rework its Asia network map to make it competitive with the other large U.S. carriers, United and American airlines, that are also vying for regional dominance.

"Without a significant network restructuring, Delta's position in the region would be significantly weakened," Vinay Dube, Delta's senior vice president of Asia Pacific, said in a blog post.

Delta inherited a robust aviation heritage in Japan, and Asia as a whole, in 2009 when it acquired Minnesota-based Northwest Airlines, which had been the first U.S. airline to fly direct to Tokyo after World War II. But over the years, United and American outmaneuvered Delta by forming partnerships with Japanese carriers.

That left Delta in a vulnerable position, the company argued in February, if more U.S. traffic shifted away from Narita to Haneda. Delta has fewer connecting routes to other Asian destinations via Haneda because it lacks the local partners with fortress hubs there.

"By forcing Delta to maintain a split operation in Tokyo with operations at both [Haneda] and [Narita], valuable traffic will be siphoned away from Delta's remaining [Narita] flights to competitors' more convenient [Haneda] flights," Dube said.

Delta executives say they are still committed to Asia as a fast-growing economy that's important to its customers. In addition to using its MSP and Los Angeles flights to reach Haneda, Dube said its future strategy will be to do more nonstop flying directly between points in the U.S. and Asia rather than hub-and-spoke flying, which is industry parlance for funneling passengers through major ports and then connecting through to their destination in a spiderweb-like network.

Delta has been building up its Seattle base in recent years to handle more nonstop flights deeper into Asia.

For now, the airline plans to continue flying to Narita from Seattle, Portland, Detroit and Atlanta, Dube said.

While Delta lacks Japanese partners, it does have arrangements with others in Asia, including China Eastern, China Southern, Korean Air, China Airlines, Vietnam Airlines and Garuda Indonesia.

Kristen Leigh Painter • 612-673-4767