Failed talks at the world's biggest copper mine last year led to a 44-day strike that pushed copper prices higher. BHP (ASX: BHP) was up around 2% at the time of writing.
The copper spot price rose above US$7,211 per tonne on the London Metal Exchange yesterday, its highest point this year.
In Australian trade, copper miner Sandfire Resources (ASX: SFR) reached a fresh all-time high today.
It had risen about 4% in late afternoon trade, on top of yesterday's gains which were made on the back of high-grade assay results from its Morck's Well farm-in, about 22km south-west of its flagship DeGrussa copper mine in Western Australia.
The copper sector was the strongest performer among the S&P/TSX Composite Index's metals and mining stocks yesterday, rising 5.74%.
First Quantum Minerals (TSX: FM) was behind the gain, rising 7.09%. The copper miner is also developing the large-scale Cobre Panama copper project in Panama.
Copper producers Freeport-McMoRan (NYSE: FCX) rose 3.12% yesterday, Antofagasta (LSE: ANTO) was up 3.14% in London and Rio Tinto (LSE:RIO) closed 3.3% higher.
AIM-listed, Africa-focused project generator Altus Strategies joined the TSX Venture Exchange yesterday, where it closed down about 8% to C11c.
Finally, attention is expected to turn to the G7 Summit starting in Quebec tomorrow, between leaders of Canada, France, the UK, US, Germany, Japan and Italy.