* Nikkei seen hovering near 14,000 amid U.S. uncertainty * JAL bucks weakness after seeking revision on Haneda slots By Ayai Tomisawa TOKYO, Oct 7 (Reuters) - The Nikkei share average extended losses into a fourth session on Monday after a weekend with little progress in resolving the U.S. budget standoff left investors frustrated, with U.S.-reliant exporters like Toyota Motor coming under pressure. The Nikkei was down 0.5 percent at 13,951.84 in midmorning trade, after dropping 0.9 percent to a one-month closing low on Friday. Republican House Speaker John Boehner vowed on Sunday that there was "no way" Republican lawmakers would agree to a measure to raise the debt ceiling unless it included conditions to rein in deficit spending. The comment raised fears that the U.S. Congress and President Barack Obama could fail to reach a deal on raising the ceiling by Oct. 17, when the Treasury has estimated it will have run out of cash. Among exporters with high exposure to the U.S. market, Toyota Motor Corp fell 0.3 percent, Sony Corp shed 0.5 percent and Subaru-maker Fuji Heavy Industries Ltd dropped 1.6 percent. But Japan Airlines Co rose 3 percent after the airline on Friday asked the government to revise its decision to allocate the majority of new international slots at Tokyo's Haneda airport to rival ANA Holdings. "Whether the government will revise this decision is unknown, but JAL's action is creating hopes that it may," said a fund manager at a Japanese asset management firm. Market observers said Japanese stocks may stay sluggish for the time being, with the Nikkei hovering around the 14,000-mark. "It's scary to either buy or sell while the U.S. situation could go either way," said Makoto Kikuchi, chief executive of Myojo Asset Management. "But investors' patience may run out, and such a mood may trigger a fall in the dollar against the yen and selling in Japanese shares." Japanese equity markets have been under pressure as the deadline to raise the U.S. federal borrowing limit gets closer. The Nikkei is down 5.8 percent from a two-month high hit in September after the Federal Reserve surprised markets by deciding not to start tapering its monetary stimulus just yet. Some remain cautiously optimistic. "I think those who wanted to take profits from the recent rises are using this event as a reason to do so. If the market is sold to a comfortable level, such dips will create bargain hunting opportunities," said Toru Ibayashi, executive director at UBS Securities.