While concerns about proposed U.S. import tariffs inflated the regional premium and concerns about economic growth for the broader market, U.S. copper prices continued their gains on Thursday, outperforming the benchmark index from London.

Copper at three months on the London Metals Exchange lost 0.5% to $9,415 per metric ton in trade at the official auction. The most active copper futures contracts in May on the American stock exchange Comex rose by 1% to $4.634 per pound. According to WisdomTree commodity strategist Nitesh Shah, “trade discussions are adding levels of uncertainty to base metals markets

The Comex copper premium compared to the LME contract increased to 764 dollars per ton against 633 dollars on Wednesday. At the same time, LME aluminum increased by 0.4% to $2,642 per ton as part of official activity, zinc gained 0.8% to $2,835 and nickel gained 1.5% to $15,810 while lead lost 0.3% to $2,004. LME tin fell 1.7 percent to $31,850 while the April contract on the Shanghai Futures Exchange fell 3.7 percent, which analysts attributed to expectations of a resumption of supplies from the main supplier, Myanmar's Wa State