* Nikkei rises 1.1 pct; Topix up 0.9 pct * Yen touches 8-1/2-month low vs dollar, buoys exporters By Dominic Lau TOKYO, Dec 13 (Reuters) - Japan's Nikkei average climbed above 9,700 on Thursday for the first time since early April as exporters were buoyed by a weaker yen on mounting expectations the Bank of Japan will implement more aggressive monetary easing. The Nikkei was up 1.1 percent at 9,699.13 in midmorning, after trading as high as 9,706.84. The gain on Thursday took the benchmark deeper into "overbought" territory, with its 14-day relative strength index at 74.6. Seventy or above is considered overbought and often signals a possible near-term pullback. Shoichiro Yamauchi, a technical analyst at Nomura Securities, said the Nikkei would test 9,800 despite the technical signals. "We think the yen depreciation will continue," he said, adding that he expected the Nikkei to rise to 10,250 by February or March. Exporters were in demand, with Toyota Motor Corp, Honda Motor Co, Canon Inc, TDK Corp and Panasonic Corp up between 1 percent and 6.1 percent. A softer yen increases exporters' overseas earnings when repatriated, and boosts their competitiveness. The broader Topix index advanced 0.9 percent to 798.35. The yen hit an 8-1/2-month low of 83.43 yen to the dollar on Thursday as investors bet on bolder moves by the BOJ after a general election on Sunday. Shinzo Abe, the leader of the main opposition party which is expected to win the election, has called for the central bank to adopt extreme policy action, including setting an inflation target of 2 percent and embarking on "unlimited easing". His comments have weakened the yen over the past month, while the Nikkei has rallied 11.8 percent, taking its year-to-date gain to 14.6 percent and narrowing the gap with the performance of its peers in the United States and Europe. The S&P 500 has risen 13.6 percent so far this year and the pan-European STOXX Europe 600 has gained 14.8 percent. Still, Japanese equities are slightly cheaper than their U.S. peers, with a 12-month forward price-to-earnings ratio of 12.1 versus the S&P 500's 12.6, data from Thomson Reuters Datastream showed.