MELBOURNE, March 14 (Reuters) - London metals logged a slow start on Wednesday as concerns about an escalation in U.S. trade tariffs kept traders cautious, although better-than-expected China industrial production figures for the start of the year lent support to prices. China's industrial output expanded faster than expected at the start of the year, suggesting the world's second-biggest economy has sustained solid momentum despite a crackdown on polluting industries and a campaign to reduce risks in the financial system. "On the face of it, (the China data) looked fairly positive for me. The fixed asset investment was obviously much better than expected and also the property investment as well," said analyst Daniel Hynes of ANZ in Sydney. "So commodity markets should have been buoyed by that, but I think the issues around the U.S. tariffs are clearly having a bigger impact on sentiment at the moment." FUNDAMENTALS: * London Metal Exchange copper cut early losses to trade up by 0.4 percent to $6,970 a tonne by 0313 GMT, adding to a 0.5 percent gain in the previous session, when prices edged up as the dollar fell. LME copper dipped to its lowest in a month at $6,777 a tonne last week. * Shanghai Futures Exchange copper climbed by 0.5 percent to 52,200 yuan ($8,266) tonne. * TARIFFS: U.S. President Donald Trump is seeking to impose tariffs on up to $60 billion of Chinese imports and will target the technology and telecommunications sectors, two people who had discussed the issue with the Trump administration said on Tuesday. * ALUMINIUM: China's aluminium production fell 1.8 percent in January-February from a year earlier, data showed on Wednesday, as the country's pollution crackdown and supply-side reform kicked in even as new smelters are due to come onstream this year. * ALUMINIUM PREMIUMS: Tariffs on aluminium imports to the United States that will begin from next week have boosted U.S. aluminium premiums. Premiums have almost doubled to 19 cents per pound from 10 cents in late January. * DEMAND: Japan's core machinery orders rebounded in January from a steep decline the previous month, handily beating expectations in a sign that capital spending will continue contributing to economic growth. * COPPER MINING: For years Rio Tinto has been the sole international copper mine operator in Mongolia, bound closely to a country where it has bet billions of dollars on the giant Oyu Tolgoi project. That is changing as a bunch of smaller players raise their exploration in the country.