LONDON: Copper prices fell on Thursday as profit-taking on Federal Reserve policymakers' concern about US growth was reinforced by doubts over whether a recent price rally was justified by the fundamentals. Benchmark copper on the London Metal Exchange (LME) was down 1.2% at $6,606 a tonne at 1602 GMT.

Prices of the metal used widely in the power and construction industries touched $6,707 on Wednesday, the highest level since June 2018 and a gain of more than 50% since economic activity stalled in March because of Covid-19 lockdowns.

Concern over supply on the LME market have been fuelled by copper stocks in LME-registered warehouses at 13-year lows of 104,425 tonnes and cancelled warrants - metal earmarked for delivery - at 50% of the total.

Aluminium was down 0.2% at $1,789 a tonne, zinc slipped 1% to $2,480, lead fell 1.2% to $1,988, tin ceded 0.6% to $17,530 and nickel was down 0.6% at $14,635.