In the runup to next week's U.S.-Japan aviation talks in Washington, a top executive of Northwest Airlines, Inc. pointed out a problem Wednesday with a new proposal for allocating slots at congested Narita airport.Richard Hirst, senior vice president of the carrier, said at a news conference that the proposal to transfer unused Federal Express Corp. slots at the airport to nonincumbent U.S. carriers is problematic. "Under the slot allocation proposal, only U.S. carriers receive slots. One of the problems with this proposal is (that it will) bypass a (new) procedure," said Hirst, referring to a new Transport Ministry rule for reallocating unused slots at Narita among all waiting airlines.A proposal has been made to transfer the unused slots of incumbent cargo carrier Federal Express, a U.S. firm with sizable aviation rights under the existing bilateral agreement, to U.S. carriers as a way to satisfy their demands.The ministry indirectly supports the slot transfer proposal, saying the issue is a domestic matter in the United States and that there are precedents for such transfers. Hirst also showed support for the "same country code-sharing," which allows two airlines based in the same country to conduct code-sharing operations -- another important issue in the aviation talks.Hirst pointed out that while Northwest Airlines supports the "open skies" policy to fully liberalize the market, the carrier also sees benefits in the transitional agreement currently being negotiated by the two governments.