METALS-US copper hits 10-month peak while tariffs send spread over LME to record high

(Updates prices at 1700 GMT) By Eric Onstad LONDON, March 18 (Reuters) - U.S. copper prices hit a 10-month peak on Tuesday, expanding their premium over London prices to a record high as speculators boosted bets on the level of tariffs U.S. President Donald Trump may impose on the metal. The most active May copper futures on the U.S. Comex exchange HGc3 climbed 1.2% to $5.02 a pound by 1700 GMT, their strongest since May 2024. Benchmark three-month copper CMCU3 on the London Metals Exchange (LME) added 0.4% to a five-month peak of $9,904 a metric ton. "It has become all about speculating on the spread between London and New York. The big driver is whether we're going to see 25% tariffs, no tariffs or somewhere in between," said Ole Hansen, head of commodity strategy at Saxo Bank in Copenhagen. The premium on Comex copper over the LME price widened to a record $1,192 a ton on Tuesday, surpassing a peak hit on February 13, and was last at $1,162. Traders have been bidding up metals prices affected by Trump's campaign to impose tariffs on foreign imports in an effort to boost U.S. industry. LME copper has gained 12% so far this year. Trump's 25% U.S. tariffs on steel and aluminium products took effect last week and he has also ordered an investigation into potential new tariffs on copper. "As long as the tariffs have not been announced, then copper will leave the rest of the world and move to the U.S., and that will tighten the global market while leaving copper stranded in the U.S.," Hansen added. Available LME copper inventories MCUSTX-TOTAL , those that have not been earmarked for delivery, have more than halved over the past month to 123,150 tons as traders seek to ship material to the United States. Weighing on other metal prices was disquiet over the economy in top metals consumer China. "Ongoing weakness in the Chinese property market continues to cast a shadow over metals demand, offsetting the government’s latest efforts to boost consumption," Neil Welsh at Britannia Global Markets said in a note. Among other metals, LME aluminium CMAL3 dropped 1.2% to $2,655.50 a ton, nickel CMNI3 shed 1% to $16,265, zinc was little changed at $2,957 and tin CMSN3 rose 0.5% to $35,345 while lead CMPB3 added 0.5% to $2,093. (Reporting by Eric Onstad; Editing by Devika Syamnath and David Goodman ) ((eric.onstad@thomsonreuters.com; +44 20 7542 7093; Twitter https://twitter.com/reutersEricO; Reuters Messaging: eric.onstad.thomsonreuters.com@reuters.net)) (( For related news and prices, click on the codes in brackets: LME price overview RING= COMEX copper futures 0#HG: All metals news MTL All commodities news C Foreign exchange rates FX= SPEED GUIDES LME/INDEX ))