(Updates prices) LONDON, May 25 (Reuters) - Copper prices slipped on Tuesday as the market fretted over China’s crackdown on prices of industrial materials, but a weaker dollar and expectations of robust demand and tight supplies helped to support sentiment Benchmark copper on the London Metal Exchange (LME) was down 0.3% at $9,919 a tonne at 1555 GMT. Prices of the metal used widely in the power and construction industries have fallen 7% since hitting a record high at $10,747.50 a tonne this month. Much of the drop came after China raised margins for futures trading and transaction fees and introduced punishment for futures violations ranging from excessive speculation to the spreading of fake news. “China’s imminent policy target is to curb the pace of price rises and to give downstream sectors some breathing time, but not to kill the rally entirely,” said Citi analyst Max Layton. “But since most of these measures do not alter underlying supply/demand fundamentals, which are improving, we expect a renewed round of steady commodity price increases once the current knee-jerk price corrections run their course.” CHINA PLAN: China will strengthen commodity price controls in its 14th five-year plan from 2021 to 2025, making plans to cope with abnormal fluctuations in the prices of commodities, including iron ore, copper and corn. DOLLAR: The dollar hit 4-1/2 month lows against a basket of currencies, as softer U.S. data and comments from Federal Reserve officials on monetary policy allayed investor fears of inflation forcing interest rates higher. A lower U.S. currency makes dollar-priced commodities cheaper for holders of other currencies, which could boost demand. TECHNICALS: Upside resistance for copper prices comes in at the 21-day moving average of $10,100 while a trendline and the 50-day moving average provide strong support at $9,400. WARRANTS: Worries about copper supplies <0#LME-WHL> on the LME market have emerged after data from the exchange showed heavy holdings with a single company. OTHER METALS: Aluminium was down 0.4% at $2,376.5 a tonne, zinc rose 1.1% to $2,980, lead gained 1% to $2,162, tin ceded 0.1% to $29,435 and nickel was down 0.7% at $17,005. (Reporting by Pratima Desai Editing by Barbara Lewis and David Goodman) Our Standards: The Thomson Reuters Trust Principles.