The share market is slightly lower due to falls by major energy and mining stocks.

Oil and gas giant Woodside Petroleum had slid more than six per cent after it revealed a massive slump in full year profit and cut to dividends, and fellow energy producers Oil Search and Santos were also significantly weaker.

BHP Billiton was another weight on the market, down nearly three per cent, and Rio Tinto was almost one per cent lower.

Biotech CSL, another market heavyweight, was down more than five per cent.

The big four banks offered some support, with NAB the best performer, adding more than one per cent.

ANZ was relatively flat after lifting its quarterly cash earnings but forecasting a greater expense from doubtful business loans.

KEY FACTS:

* At 1211 AEDT on Wednesday, the benchmark S&P/ASX200 index was down 7.4 points, or 0.15 per cent, at 4,902.6 points.

* The broader All Ordinaries index was down 4.3 points, or 0.09 per cent, at 4,957.3 points.

* The March share price index futures contract was down 14 points at 4,861 points, with 22,048 contracts traded.

* National turnover was 768 million securities traded, worth $1.8 billion.