* S&P 500 and Dow Jones Industrial Average fall overnight

* Investors eye the outcome of the U.S. Federal Reserve's meeting

* Energy stocks fall as oil prices slump

March 17 (Reuters) - Australian shares opened lower on Wednesday after gaining for the past three sessions, as energy and mining stocks fell, and as Wall Street slid ahead of the outcome of the U.S. Federal Reserve's policy meeting later in the day.

The S&P/ASX 200 index slipped 0.36% to 6,827.1 by 2330 GMT.

The S&P 500 and the Dow Jones Industrial Average fell overnight as investors looked to the results of the U.S. central bank's meeting amid fears about an overheating economy, although no major policy change is expected.

Among individual sectors and stocks, miners fell 1.2% as copper prices slumped after investors shed some bullish positions due to uncertainty ahead of central bank meetings.

Global miners BHP Group and Rio Tinto were down 1.1% and 1.3%, respectively.

Energy stocks also declined as oil prices fell after some European countries halted the use of a major coronavirus vaccine, threatening the recovery of fuel demand.

Oil & gas explorers Woodside Petroleum and Santos Ltd were down 0.6% and 0.5%, respectively.

Gold stocks snapped two straight sessions of gains to fall 1.5% as prices of the yellow metal weakened against a stronger dollar, with top gold miner Newcrest Mining down 1.3%.

The number of issues on the ASX that advanced were 506 while 600 declined.

New Zealand's benchmark S&P/NZX 50 index was unchanged in early trade, as gains among utility and energy stocks were offset by losses among financials.

Dairy exporter Fonterra on Wednesday reported a 43% surge in adjusted profit and said it would sell its joint venture farms in China. The company's stock was 0.2% lower.

(Reporting by Soumyajit Saha in Bengaluru; editing by Uttaresh.V)