* Westpac flags $233 million hit to H2 cash earnings
* Rio Tinto (LON:RIO) up on plans to review NZ aluminium smelter
* NZ index records worst session in over 2 mths (Changes throughout, updates to close)
Oct 23 (Reuters) - Australian shares ended flat on Wednesday as gains in miners were offset by profit-taking in the healthcare sector, while New Zealand's market was hit by steep looses for energy stocks after Rio Tinto said it plans to shut a power-guzzling smelter.
The benchmark S&P/ASX 200 index .AXJO was little changed at 6,673.10 points, having advanced 0.3% on Tuesday.
Healthcare firms .AXHJ were the among the worst performers, falling as much as 1.5% during the session before ending 0.4% lower.
"It's simply a bit of profit-taking or rebalancing of portfolios right now in the health space," said Brad Smoling, managing director at Smoling Stockbroking.
Buying of defensive stocks has pushed the sector up nearly 30% this year, making it one of the top gainers on the ASX 200.
Australia-listed shares of Resmed Inc RMD.AX declined 2.7%, while Sonic Healthcare SHL.AX lost and Pro Medicus PME.AX lost 1.3% and 6.1%, respectively.
Financial stocks .AXFJ were slightly lower, with No. 2 lender Westpac Banking Corp WBC.AX falling 0.2%. The bank said its cash earnings in the second half of 2019 would be reduced by about $233 million due to customer remediation programmes. the mining sector, heavyweight Rio Tinto Ltd RIO.AX rose 0.4% after it flagged a possible pullback or closure of an "unprofitable" aluminium smelter in New Zealand. Metals Group FMG.AX ended up 2.2%, a day before it is due to report its first-quarter production results.
Gold stocks .AXGD rose 0.3%, as bullion prices inched up from increased tensions over Brexit. GOL/
Miner Gold Road Resources Ltd GOR.AX rocketed 12% and was the largest gainer on the ASX 200 after RBC upgraded the stock.
New Zealand shares clocked their worst intraday session in more than two months, as utilities were stung by Rio Tinto's plan to shut its aluminium smelter, the largest single power consumer in the country.
The benchmark S&P/NZX 50 index .NZ50 declined 2.1% or 236.60 points to 10,853.79.
Meridian Energy Ltd MEL.NZ slid nearly 8.7% to a near two-month closing low. The company is the main supplier of electricity to the Rio Tinto smelter.
Peers Contact Energy Ltd CEN.NZ and Mercury NZ Ltd MCY.NZ fell 9.7% and 8.4%, respectively.
Brokerage UBS in a note said that closure of the site "would have significant short, medium and long term consequences across the New Zealand utilities space and more broadly for New Zealand".