Three-month copper on the London Metal Exchange was down 0.5 percent at $6,372 a tonne in official outcry rings, having hit its highest since July 10 at $6,426.50 in the previous session.
On Wednesday LME copper broke through technical resistance at $6,400, which triggered profit-taking alongside a stronger dollar, said Saxo Bank commodities analyst Ole Hansen.
"But overall the story driving copper is the worries about supply," he said.
Miner and trader Glencore on Tuesday lowered its 2019 copper output forecast to 1.5 million tonnes from 1.54 million tonnes, citing production cuts at its Mutanda mine in the Democratic Republic of Congo.
"(That) supports the idea that supply is tightening in copper and has helped it move ahead despite the headwinds from the uncertainty related to global economic growth," Hansen said.
The metal used in power and construction has registered reduced inventories while supply has been constrained by lack of investment in mines and declining grades.
Stocks of copper in LME warehouses stand at 137,700 tonnes, close to 10-year lows of 122,500 tonnes hit in early December last year.
The US currency gained against a basket of major currencies. A stronger greenback makes dollar-denominated commodities more expensive for non-US firms in a relationship used by funds to generate buy and sell signals.
The United States and China have started to outline commitments in principle on the stickiest issues in their trade dispute, the most significant progress yet toward ending a seven-month trade war, sources said.
Signs of progress in trade talks usually boost metals and equities, but markets had been "brewing on that theme for too long and most of the positive news has been priced in already", said Saxo Bank's Hansen.
Intense rains at the start of this month in Chile, the world's top copper miner, are likely to have hurt productivity at state-owned Codelco's Chuquicamata and Radomiro Tomic mines, the country's mining minister said.
The premium for cash zinc over the three-month LME contract rose to $26.50 as stocks in LME warehouses fell to their lowest since 2017 at 83,250 tonnes.
Aluminium was bid up 0.5 percent to $1,875 after failing to trade in official rings.
Zinc was bid down 0.9 percent to $2,674, lead was bid 0.4 percent higher at $2,048, tin was bid at a little changed $21,275 and nickel traded 0.8 percent higher at $12,800.