It was a slow start for trading, with Australian shares opening slightly lower as optimistic investors turned cautious about US budget negotiations.

The S&P/ASX 200 index managed to pick up pace before the afternoon, hitting an intraday high of 4643.4 points at about 11am AEDT.

The index managed to close up 0.3% or 16.3 points to 4634.1 points and the broader All Ordinaries also added 0.3% to 4646.6 points.

Basic materials dipped 0.2%, while oil and gas and technology fell 0.8% and 1.3% respectively.

Posting gains was the health care sector, up 0.6%, while financials had a good run after firming 0.7%.

There were more miners at a loss today, with majors BHP Billiton and Rio Tinto dropping back.

Rio closed down 0.6% to $A65.30 and BHP finished 0.05%, or 2c, lower at $37.04.

Some of the iron ore players fell into the red, with Fortescue Metals Group losing 3.4% to $4.50.

Grange Resources sank 6.9% to 27c and Mount Gibson Iron fell back 4.3% to 77c.

Gold producers were mixed, with Newcrest Mining dipping 0.3% to $22.49 while Alacer Gold Corporation jumped 0.7% to $4.47 and Silver Lake Resources retreated 2.1% to $3.23.

OceanaGold Corporation managed to gain back ground lost yesterday, closing up 1.9% to $2.70.

After tumbling almost 10% yesterday, shares in OZ Minerals closed up 3% to $6.91 after responding to a price query.

Shares in Rox Resources extended gains following news of a nickel sulphide discovery at its Fisher East project.

Rox jumped a massive 131.8% to 5.1c.

At the opposite end, Renison Consolidated Mines shed 30.2% to 3.7c on no news.

The Australian dollar was trading slightly lower at $US1.047.