TOKYO, Oct 9 (Reuters) - Japanese stocks posted their biggest weekly gain in two months on Friday, on hopes of more stimulus in the United States, even though some investors doubted the chances of a deal in the run up to the U.S. presidential election.

The Nikkei 225 Index ended 0.12% lower at 23,619.69 on Friday. For the week, the Nikkei added 2.6%, its largest gain since the week ended Aug. 14. The broader TOPIX fell 0.49% to 1,647.38. For the week, the TOPIX rose 2.4%.

U.S. President Donald Trump said talks with Congress about a coronavirus stimulus, which he had abruptly called off earlier this week, had restarted.

However, Democrat House Speaker Nancy Pelosi downplayed the likelihood of stand-alone bills, and relations between the two political parties are likely to become more strained as a hotly-contested presidential election on Nov. 3 draws near.

The U.S. economy, struggling with a rise in cases of the novel coronavirus, is certain to lose momentum without a new stimulus — a risk for Japan's export sector.

"The biggest factor is (that) there is a great lack of clarity about U.S. economic policy and the presidential election, which is why it's difficult for markets to move," said Kiyoshi Ishigane, chief fund manager at Mitsubishi UFJ Kokusai Asset Management.

The largest percentage losers on the Nikkei index were Mitsubishi Motors Corp down 4.24%, followed by Takashimaya Co Ltd losing 4.22%, and JGC Holdings Corp down by 3.55%.

The largest percentage gainers were Seven & i Holdings Co Ltd up 4.61%, followed by Fast Retailing Co Ltd gaining 2.87%, and Daikin Industries Ltd up by 2.81%.

There were 41 advancers on the Nikkei index against 179 decliners.

The volume of shares traded on the Tokyo Stock Exchange's main board was 0.91 billion, compared with the average of 1.15 billion in the past 30 days. (Reporting by Stanley White; editing by Uttaresh.V)