LONDON, July 9 (Reuters) - U.S. copper futures widened their premium to the London benchmark on Wednesday, reflecting U.S. President Donald Trump's plan to impose a 50 percent tariff on imported copper.
* "I think we're going to put the tariff on copper at 50%," Trump told reporters at a White House Cabinet meeting on Tuesday. Commerce Secretary Howard Lutnick indicated the tariff is likely to take effect on August 1 or even earlier.
* The premium on the most-active COMEX copper futures contract to the London Metal Exchange's (LME) three-month benchmark jumped to 26% from 13% before the announcement.
* "This is a defining moment for the copper market in 2025, as the impending implementation of steep tariffs should abruptly close the window for significant new copper shipments to the United States," Citi analysts said in a note.
* LME copper fell 1.6% to $9,635.50 a tonne by 1636 GMT, after touching $9,553.50, its lowest since June 13. COMEX copper hit a record high on Tuesday but was down 3.5% on the day at $5.587 a pound.
* The COMEX-LME arbitrage remained below the expected 50% rate as the market awaits more clarity on which products and suppliers will be affected by the tariff. The largest U.S. Suppliers—including Chile and Canada—are likely to receive a lower levy of 25%, according to Citi.
* The massive influx of copper into the United States since Washington began its investigation into possible copper tariffs in February also limited the immediate impact of the tariff plan on U.S. consumers of the metal: the construction, electronics, and transportation sectors.
* In other base metals, LME aluminum rose 0.6% to $2,599.50 a tonne; zinc gained 0.9% to $2,743; lead gained 0.1% to $2,057.50; tin fell 0.3% to $33,245; and nickel fell 0.3% to $14,990.
