* BHP in steps to restore copper output
* Olympic Dam offline since Sept 28
* Oz Minerals back in operation (Releads with BHP mine efforts to restart)
By Tom Westbrook and James Regan
SYDNEY, Oct 13 (Reuters) - BHP Billiton BHP.AX BLT.L is preparing to return to full production at its Olympic Dam copper mine after regaining full electric power, the last of the big industrial sites in southern Australia to restart after a massive blackout two weeks ago.
"The focus now is to safely transition our surface operations from a period of care and maintenance back into full production," Jacqui McGill, president of the Olympic Dam division, said in a statement emailed to Reuters on Thursday.
The move comes after power supplier Electranet advised BHP that a final transmission line had been reactivated, enabling full power to be restored, McGill said.
Mining at Olympic Dam was halted when a storm destroyed power transmission lines and blacked out the entire state of South Australia on September 28. has been losing an average of 567 tonnes of copper production a day, costing $2.7 million a day, based on last year's output of 203,000 tonnes and current metals prices of around $4,800 a tonne, or about 13 percent of company-wide output for the world number two producer of the metal.
BHP said the impact on production will be provided on Oct 19 when it releases it next quarterly operations report.
Australia's Oz Minerals Ltd OZL.AX also said production was resuming at its neighbouring Prominent Hill copper mine after getting power back.
"ElectraNet's industrial customers now have full load levels available to them," it said in a statement.
Full production at a Nyrstar NYR.BR lead smelter resumed on Wednesday, reactivating a 185,000 tonnes-per-year facility. by)