The drop was due in part to the Escondida strike in Chile, lower grades and poor weather in the US, a three-month ban on concentrate exports in Indonesia and lower grades mined in Argentina, Canada and Mongolia, it said.
The report said refined production had increased about 0.5% and apparent refined usage had increased about 0.6%, leading to a world refined copper deficit for the period of about 195,000t.
Copper stocks rose at major metal exchanges during January but so did the average price, the ICSG noted.
The average London Metal Exchange copper cash price in January was US$7,080 per tonne, 15% higher than the 2017 annual average.
The LME cash price fell about 0.4% yesterday to $7,047/t and major copper equities closed lower around the world.
Diversified miner BHP fell more than 4.7% today in Australian trade, in the wake of yesterday's interim results.
In London, Rio Tinto (LN:RIO) and Antofagasta (LN:ANTO) closed down about 1.6% and 0.5% respectively.
Freeport-McMoRan (US:FCX) was down 1.6% in New York and First Quantum Minerals (CN:FM) lost just over 1% in Toronto.