* Dollar index near six week high * Tin at one month high on Indonesian shipments halt * Coming up: U.S. ADP employment for August at 1400 GMT By Veronica Brown and Harpreet Bhal LONDON, Sept 5 (Reuters) - Copper prices were little changed on Thursday, with a strong dollar putting pressure on base metals and offsetting optimism about a revival in demand from top consumer China. Three-month copper on the London Metal Exchange was at $7,138 a tonne at 1017 GMT, up slightly from a close of $7,134 on Wednesday when the metal used in power and construction fell close to 2 percent. Putting pressure on metals were gains in dollar against a basket of currencies, which traded near a six-week high. A strong dollar makes commodities priced in the U.S. unit more expensive for holders of other currencies. The dollar was supported by expectations that the U.S. Federal Reserve could begin to withdraw stimulus measures as early as this month due to signs of improvement in the economy. "You have a Fed that is poised and ready to start tapering and I think they want to go ahead with this as they feel they are in danger of expanding their balance sheet too much," said Nic Brown, head of commodities research at Natixis. "It may well be possible to give the market some reassurance in the form of stronger forward guidance to offset withdrawal of some of the liquidity being injected currently through Q.E." Investors are expected to closely monitor key U.S. jobs figures, due on Friday, for further evidence of the pace of recovery in the world's largest economy. The U.S. economy expanded at a "modest to moderate" pace in most of the country between early July and late August, according to a Federal Reserve report that was just strong enough to reinforce the prospect of a pullback in monetary stimulus. Helping to keep prices from falling further were expectations of a rebound in demand from China, where economic data has been pointing to a recovery in the world's second largest economy. Recent figures showed growth in China's services sector hit a five-month high in August, underpinned by optimism over government policy measures. "We've had some decent PMI around the world in the last week, Chinese numbers are now looking significantly more positive, the U.S. numbers still look decent and there have been some pleasant surprises in Europe, so generally the economic data is looking a little more solid," Brown said. Benchmark tin prices rose to a one-month high at $22,285 a tonne after Indonesia's No. 1 tin exporter, state-backed PT Timah, said it halted shipments and declared force majeure, blaming new trading rules and dealing a blow to government efforts to boost the nation's influence in commodity markets. The shortfall in supply has helped drive up cash prices to a $125 premium against the benchmark three-month contract during Wednesday's evaluation, the highest level since August 2010.

Source