* Fuji Media, Dentsu sag after BofA ML downgrades * Japan Tobacco extends losses on EU probe report * Goldman Sachs remains upbeat on the market By Dominic Lau TOKYO, Aug 22 (Reuters) - Japan's Nikkei share average fell on Wednesday as investors cashed in gains after a recent sharp run-up on mounting expectations that the European Central Bank will soon act to tackle the euro zone sovereign debt crisis. Having banked on some action by the ECB, investors have become impatient for positive signs that the central bank will indeed agree details for a bond buying programme to bring down punishingly high borrowing costs for countries like Spain and Italy. "That's why people are taking profits today," said Kyoya Okazawa, head of equity and derivatives at BNP Paribas in Tokyo. The Nikkei dropped 0.9 percent to 9,078.03, taking the benchmark to below its five-day moving average at 9,132.27 and its 26-week moving average at 9,146.46. Investors became edgy after the ECB on Monday quashed speculation about the shape any bond buying programme might take, saying it was premature as decisions had not been made. Previously, hopes of firm action by the ECB to ease the euro zone debt crisis had helped the Nikkei rebound 1 0 p ercent from a seven-week low touched on July 25. It touched a three-month high on Monday and the Nikkei is up 7.4 percent so far this year. Trade figures released on Wednesday cast more gloom over the outlook, as Japan's exports slumped the most in six months in July as sales to a debt-ridden Europe and a sluggish China dropped. Fuji Media Holdings shed 4.7 percent and Dentsu Inc , Japan's largest advertising agency, fell 4.3 percent after Bank of America Merrill Lynch downgraded its ratings on the two companies to 'neutral' from 'buy' and lowered their price targets, citing expectations of slower demand in advertising from autumn. A Deutsche Bank downgrade to 'hold' from 'buy' also weighed on Dainippon Screen Manufacturing Co Ltd, which lost 4.5 percent. JAPAN TOBACCO UNDER SPOTLIGHT Japan Tobacco Inc eased 1.1 percent, extending the previous session's 1.7 percent drop after the Wall Street Journal said the European Union is investigating whether a sale of cigarettes by a Swiss-based unit of Japan Tobacco to a firm linked to cousins of Syrian president violated its sanctions against Syria. The broader Topix index fell 0.8 percent to 759.04. Trading volume on the index after the morning session was light, at 37 p e rcent of its full daily average for the past 90 days. Investors were cautious ahead of the release of the minutes of the latest Federal Reserve policy committee meeting on July 31-Aug. 1. "People are waiting what comes out of the FOMC (minutes). There is no reason to do much in the market," a senior trader at a foreign bank said. He said there were a few domestic players selling in the last few days but in general it was a mixed bag as volume was light. Goldman Sachs reiterated its six- and 12-month Topix targets of 850 and 930 respectively, or 11 and 22 percent upside from Tuesday's close. "The combination of dissipating global macro risks and improving domestic macro and micro fundamentals will help lower the market's risk premium and drive Topix higher," Goldman Sachs said in a report. "Given the sharp rise in just the past four weeks, we expect the market to digest recent gains near-term," it said, adding that its three-month target remained 775. The brokerage said it was overweight capital goods, transportation, automobiles, banks and real estate.