MELBOURNE, Jan 21 (Reuters) - South32 Ltd S32.AX has cut net debt by about 70 percent since the end of June to $115 million, it said on Thursday, shoring up the miner of coal and metals against shrinking earnings from weaker output and plunging prices for most of its commodities.
South32, spun off last year by BHP Billiton BHP.AX BLT.L , has already cut or suspended output at its high cost South African manganese ore mines, and some smelters and said it would do more to help it ride out the tough market.
"Further decisive action will be taken as we seek to maximise short-term cash flow, while preserving longer-term value," Chief Executive Graham Kerr said in a statement.
South32 cut its forecast output of Australian coal by 7 percent to 8.3 million tonnes for the year to June 2016 after running into geological challenges at two mines.
However, it reaffirmed full-year output guidance for its other products, including alumina, South African coal, nickel, silver, lead and zinc, while it continues a review of its South African manganese operation.
Except for zinc, all production is expected to be lower than last year.
Zinc output in the December quarter rose 31 percent from a year earlier to 22,200 tonnes, well ahead of a Goldman Sachs' forecast of 18,794 tonnes, boosted by a sharp improvement in the amount of ore recovered per tonne of rock.
South32's shares, down 58 percent since they listed last May, rose 1.1 percent on Thursday after the production report, roughly in line with the broader market.