Mining stocks led Australian shares lower on Wednesday ahead of the US Federal Reserve's rate decision, with investors on the lookout for any mention of the pace of hikes this year.
Markets expect the Fed to raise rates for the second time in the year but caution prevails as investors await its language on the pace of further tightening.
The benchmark S&P/ASX 200 index was down 0.5 per cent or 30.9 points, to 6,023.5. It added 0.2 per cent on Tuesday.
The index of mining stocks accounted for most of the main index's fall, extending losses to a third session on weakness in base metal prices.
A hike in interest rates can strengthen the dollar and make dollar-denominated metals pricier for holders of other currencies.
Heavyweight BHP Billiton was the benchmark's top drag, down 1.3 per cent . Rival Rio Tinto lost 1.2 per cent .
Australia's "Big Four" banks also sapped sentiment, shedding between 0.3 per cent and 1 per cent .
Commonwealth Bank of Australia finished at its worst level since 2013.
Gas pipeline company APA Group propped up the main board, rising nearly 21 per cent to a record close following a $9.81 billion takeover offer from a consortium led by Hong Kong's CK Infrastructure Holdings.
In a busy day for deals, Australian billionaire Gina Rinehart's Hancock Prospecting Pty Ltd group of companies disclosed a 19.96 per cent stake in Atlas Iron Ltd, joining the race for the small iron ore miner.
Atlas closed at its highest in over a year, up 6 per cent .
Also, France's ERAMET upped its offer price for Australia's Mineral Deposits Ltd by nearly 20 per cent but Mineral Deposit's shares still dropped 4.5 per cent .
Blackstone Group signed an agreement to buy Australia's Investa Office Fund for $2.3 billion, helping Investa shares up 0.2 per cent . Gateway Lifestyle Group gained over 14 per cent on Hometown's buyout proposal that values the company at $480 million.
Meanwhile, New Zealand's benchmark S&P/NZX 50 index erased earlier losses to surge to its best close of all time, up 18.5 points to 8,977.31. Healthcare stocks were the star performers.
Fisher & Paykel Healthcare Corporation, up 1.6 per cent , gained for a tenth straight session to scale a record close.