Benchmark copper prices rallied 12 percent in December, partly due to fear of shortages if workers go on strike since many major operations in top producers Chile and Peru have contacts expiring this year, including at top mine Escondida.
Chile's state-owned Codelco said late last month it had struck a contract deal with workers at its Andina copper mine, while workers at the Lomas Bayas mine accepted a contract offer from operator Glencore Plc (>> Glencore) early in January.
"The risk of disappointment is probably as big as the risk of it (strikes) coming to fruition because just take a look at what happened last year," said Ole Hansen, head of commodity strategy at Saxo Bank in Copenhagen.
"We had some quite significant disruptions and the price did not actually move that much at the time."
LME Benchmark Copper Price: http://reut.rs/2EuGiso
The world's biggest copper mine, Chile's Escondida, was hit by a six-week strike last year, pushing down output at the operation by 7.8 percent to 903,000 tonnes in 2017.
The strike ended when the union representing the striking workers opted to return to work under the old contract, effectively pushing talks on a new deal into 2018 for the mine operated by BHP (>> BHP Billiton Plc) (>> BHP Billiton Limited).
Last week, the powerful union at the mine cast doubt on chances of starting talks on a new labour agreement with the company before formal negotiations scheduled for June.
Despite the tough talking by the union, several analysts believe there will not be a repeat of last year's extended walk-out.
"Looking at the major Escondida contract due for renewal in June, we would question the appetite for either workers or mining companies to withstand another lengthy strike," ING analysts led by Hamza Khan said in a note.
Several contracts due to be negotiated at other mines are with supervisors or professionals, who are regarded as less likely to strike, UBS analyst Daniel Major said in a note.
Chile Copper Output vs BHP Shares: http://reut.rs/2EGl6xe
Even last year, when the copper market was hit by a series of disruptions, the actual amount of copper lost was less than expected, according to some analysts.
"Last year we were using 5.5 percent but as far as I've got to, it's only realising 5.2 percent so far," said analyst Vivienne Lloyd at Macquarie, adding that the last year's number could not be finalised until all the fourth quarter production reports were released.
Karen Norton at Thomson Reuters GFMS said provisional data showed a disruption rate last year of 5.1 percent, close to the long term average and lower than in 2015, when it hit 6 percent.
Lloyd estimates that the multiple mine contracts up for negotiation this year equals 31 percent of global copper production, but she does not expect extensive strike action.
Last year the world's second biggest copper mine - Grasberg in Indonesia - had stoppages linked to disputes with the government, but operator Freeport-McMoRan Inc (>> Freeport-McMoran) said on Jan. 25 it was edging closer to a permit deal after it agreed to divest a 51-percent stake in the huge mine.
"Now the government actually has the incentive to allow the mine to produce," Lloyd said. "So we actually have a lower (forecast global) disruption rate for this year, 4.8 percent."
Any loss of production through disruptions would be cushioned by an increase in inventories, Hansen said.
Total stocks in exchange-approved warehouses have gained more than a fifth since early December to over 700,000 tonnes.
Copper Mine Disruptions: http://reut.rs/2si4NEj
Exchange Copper Inventories Rise: http://reut.rs/2BGABXn
(Reporting by Eric Onstad; Editing by Adrian Croft)
By Eric Onstad