* Healthcare firm CSL biggest drag on the index
* Miners make a comeback from Monday's losses
* Challenger the top percentage gainer on the benchmark
By Nikhil Nainan
Aug 13 (Reuters) - Australian shares edged lower on Tuesday as losses among heavyweight healthcare stocks outweighed gains in the mining sector.
The S&P/ASX 200 index .AXJO was trading at 6,576.1 by 0215 GMT, down 0.2%, following a negative lead from the United States. The index had gained 0.1% on Monday.
U.S. stocks dropped in a broad sell-off overnight as tensions, including the Sino-U.S. trade war and Argentina's peso crash, spooked equity investors and sent them to the relative safety of gold or bonds.
Michael McCarthy, chief market strategist at CMC Markets Australia, said there was a big lift in trading volumes after several Asian markets were closed for holidays on Monday.
"The surge in volume suggests we are seeing dip buyers moving into the market," McCarthy said.
Heavyweight biotechnology company CSL Ltd CSL.AX fell 2%. Elsewhere in the sector Cochlear COH.AX dropped 3% and Mayne Pharma Group MYX.AX fell 3.1%.
Iron ore miners, which have come under pressure from falling prices, bounced back from losses in the previous session with Fortescue Metals Group FMG.AX leading the gains.
Fortescue rose as much as 4%, while top miners BHP Group BHP.AX and Rio Tinto (LON:RIO) RIO.AX each added 0.2%.
McCarthy said the gains in the sector appeared to be due to support from day traders, adding he wasn't "seeing much evidence that this is investment related"
On Monday, upbeat corporate earnings helped the index eke out a fourth straight session of gains, but some investors seem to be unwinding those positions on Tuesday. Bendigo and Adelaide Bank BEN.AX , Ansell ANN.AX and JB Hi-Fi JBH.AX all fell a day after reporting results.
Fund manager Challenger Ltd CGF.AX jumped 11.2% as it maintained its fiscal 2020 earnings forecast and reported flat full-year profit. Westpac Banking Corp WBC.AX outperformed its peers, rising 0.4%, after an Australian court dismissed a case by the corporate regulator against it. The regulator had claimed the country's second-largest lender used inappropriate standards to approve thousands of mortgages.
In New Zealand, the benchmark S&P/NZX 50 index .NZ50 fell 0.3%, or 30.36 points to 10,842.38.
Auckland International Airport AIA.NZ fell 1.6% while Chorus CNU.NZ dropped 2%.
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