* Upbeat global data spur broad gains * Dollar trades above 99 yen, lifting exporters * Foreigners net buyers for 1st time in 4 weeks * Short-covering lifts companies with high exposure to emerging markets By Ayai Tomisawa TOKYO, Aug 23 (Reuters) - Japan's Nikkei share average rose above 13,500 on Friday morning, with upbeat factory activity data from around the world spurring broad gains, led by exporters which got an extra lift from a weaker yen. Analysts said that investors, who have been shackled by concerns of an imminent reduction in the Federal Reserve's massive stimulus, are chasing the market higher after data from China, the U.S. and Europe suggested the global economy was on a firmer footing. The Nikkei rose 2.1 percent to 13,646.99 in midmorning trade, with resistance level of 13,781.32 in sight, a 38.2 percent retracement of the slide from its May high to the June low. On Thursday, the Nikkei dropped 0.4 percent. For the week, the benchmark is up 0.3 percent. On Thursday, purchasing managers surveys showed better-than-expected growth in the euro zone, a rebound in China's vast manufacturing sector and U.S. manufacturing activity rising to a five-month high in August. "These are positive catalysts as those countries are Japan's major export markets," said Toshihiko Matsuno, senior strategist at SMBC Friend Securities. Exporters outperformed as a softer yen provided an extra edge. Toyota Motor Corp rose 2.6 percent and was the most traded stock by turnover, Honda Motor Co gained 2.5 percent, while Sony Corp added 3.0 percent. The dollar traded above 99 yen, from around 98 yen two days ago. A weak yen lifts Japanese exporters' competitiveness overseas as well as their earnings overseas when repatriated. The Topix gained 2.0 percent to 1,142.30. "It doesn't look like investors are going long. It's merely short-covering, but compared to a few days ago when fears about emerging countries weighed, we are finally seeing bright sings in the world economy," said Isao Kubo, equity strategist at Nissay Asset Management. Emerging markets in the region, India and Indonesia in particular, have had a torrid time in recent weeks on concerns about a turn in Fed policy. Analysts cautioned that the persistent worries over the Fed's likely tapering of its stimulus, perhaps as early as next month, could draw more capital out of emerging countries. "We need to be careful of their market moves until there are more signs about the Fed's tapering," Matsuno of SMBC Friend Securities said. Companies with high exposure to emerging markets, which were battered this week, rose on short-covering, with Hino Motors climbing 5.6 percent, Isuzu Motors gaining 4.3 percent and Kubota Corp advancing 3.1 percent. Sentiment was also supported by data showing overseas investors were net buyers of Japanese stocks for the first time in four weeks in the week of August 12-16, to the tune of 99.5 billion yen. "Investors don't want to hold their selling positions over the weekend," said Hiroichi Nishi, an assistant general manager at SMBC Nikko Securities.