Base metals such as copper and aluminum advanced further, continuing a strong sector-wide rally driven by concerns over tightening supplies and increasing investor enthusiasm for commodities.

Copper, aluminum, and nickel each climbed more than 1%, with the red metal approaching the record high set earlier this week. Goldman Sachs Group Inc. raised its first-half copper price forecast to $12,750 per ton, while also noting that prices are expected to pull back in the latter half of the year.

As measured by the LMEX Index of the six main metals traded in London, base metals are on track for a fourth straight weekly gain, marking the longest winning streak since August. Copper has been particularly favored as worries that Washington will impose an import tariff have drawn metal into the US, tightening supply conditions in other regions.

"Investor inflows have added a scarcity premium to copper in the face of low ex-US inventories as the expectation of a US tariff on copper has pulled metal into the US," the Goldman analysts stated in a note. However, they added that prices above $13,000 are unlikely to be sustained, as a decision to implement tariffs "would likely signal the end of US stockpiling."

The metals outlook also garnered attention after Rio Tinto Group announced it is in discussions to acquire Glencore Plc, a move that would create the world's largest mining company. Such a tie-up would represent the biggest-ever deal in an industry currently swept by takeover fever, as producers aggressively seek to increase their copper assets.

Copper increased by 1.1% to $12,856 per ton, while aluminum gained 1%. Nickel, which surged to a 19-month high on Wednesday before falling as traders awaited specifics on output cuts from top producer Indonesia, was trading at $17,410 per ton.