Asian stocks ride US momentum, oil near 15-month high

SINGAPORE, Oct 20 (Reuters) - Asian stocks advanced on Thursday, propelled by strong U.S. earnings and oil prices near a 15-month high, as the third and final U.S. presidential debate before the Nov. 8 election got underway. MSCI's broadest index of Asia-Pacific shares outside Japan rose 0.25 percent. Japan's Nikkei extended gains to 0.9 percent. China's CSI 300 increased 0.2 percent, and Hong Kong's Hang Seng index climbed 0.6 percent. In the final debate between Republican presidential candidate Donald Trump and Democrat Hillary Clinton, which began at 0100 GMT, the former is trying to reverse the momentum in an election that polls show is tilting away from him. Trump has been damaged recently by several accusations of groping women - which he denies - and concerns about his claims that the election will be rigged against him. "One of the six topics is the U.S. economy, and any clarification of policy in this area could influence trading," Michael McCarthy, chief market strategist at CMC Markets in Sydney, wrote in a note. "Secondly, a clear win for either candidate is important. Markets are likely to buy Clinton and sell Trump." The Mexican peso inched down against the dollar on Thursday during the debate, slightly shrinking this week's gains. The U.S. dollar rose 0.2 percent to 18.548 peso on Thursday, but remains down 2.4 percent this week. With Trump's criticism of Mexican migration and trade putting the U.S's southern neighbour at a disadvantage if he wins, a stronger Mexican peso reflects market perceptions of a lower chance of a Trump win. Overnight, the S&P 500 index and the Dow Jones Industrial Average closed up 0.2 percent, after Morgan Stanley posted a better-than-expected quarterly profit to round out a string of solid results from big U.S. banks. With 70 companies in the S&P 500 having reported earnings through Wednesday morning, 80 percent have topped earnings expectations. Third quarter earnings are now expected to increase 0.5 percent, according to Thomson Reuters I/B/E/S, which would be the first quarter of growth in five. "We're up because the (earnings) numbers are so great, the forward guidance is great and the banks just knocked it out of the park," said Ken Polcari, Director of the NYSE floor division at O'Neil Securities in New York. Energy shares also contributed to the gains on Wall Street, as oil prices jumped after a surprisingly large inventory drop of 5.2 million barrels, compared with a forecast for a 2.7-million barrel build. It was the sixth week of declines in seven weeks. U.S. crude slipped 0.3 percent to $51.44 on Thursday, after surging 2.6 percent to close at $51.60 in the previous session. It earlier touched $51.93, the highest since July 2015. Brent crude was little changed at $52.64 on Thursday, after climbing 1.9 percent on Wednesday. The dollar rose 0.15 percent to 103.62 yen on Thursday after falling 0.4 percent on Wednesday. The euro was flat at $1.0974, ahead of the European Central Bank's policy meeting on Thursday. Investors are focused on whether ECB President Mario Draghi will give any indications that the central bank will begin tapering its bond purchase program when it meets on Thursday.