Copper set to snap 10-week winning streak on White House tariff hesitation

Sept 11 (Reuters) - Copper was set to snap a 10-week winning streak, despite a marginal Friday rise, after Reuters reported that the White House had yet to decide on refined copper tariffs, triggering a sharp drop from record highs.

Three-month copper on the London Metal Exchange CMCU3 was down about 1% for the week after falling more than 4% from the $14,875 a metric ton peak hit on Thursday.

On Friday, the contract rose 0.26% to $14,271 a metric ton by 0312 GMT.

The most-traded copper contract on the Shanghai Futures Exchange SCFcv1 fell 2.82% to 108,580 yuan ($16,180.85) a ton and was down about 0.5% for the week.

White House officials are weighing concerns that higher metal prices could raise manufacturing costs against the benefits of encouraging more domestic mining, Reuters reported on Thursday, citing two people familiar with the matter.

"Until now, the market had largely assumed that tariffs would go ahead," ING commodities analysts said in a note, adding that the latest news had removed some of the tariff premium from prices.

COMEX copper had traded at a premium to LME prices for months as traders shipped metal to the U.S. ahead of possible tariffs. The dwindling tariff premium following the report has made shipments to the U.S. uneconomical.

Copper stocks in COMEX warehouses HG-STX-COMEX were last reported at 767,664 short tons, or 696,413 tons, as of Thursday after months of tariff-driven inflows.

The reversal also eased tightness in London. The premium for cash copper over the three-month contract CMCU0-3 narrowed to $5 a ton on Thursday from $41 a day earlier.

ING added the rally towards $15,000 had run ahead of fundamentals, and that ruling out tariffs could send some U.S. metal back to international markets.

Among other metals on the LME, aluminium CMAL3 rose 0.29%, zinc CMZN3 gained 0.26%, lead CMPB3 was flat, nickel CMNI3 fell 0.25% and tin CMSN3 dropped 0.73%.