The sharemarket has lost its early gains as investors digest a wealth corporate earnings reports.

Stocks were buoyed in early trade after BHP Billiton reported an 83 per cent rise in half year profit.

But Commsec market analyst Juliana Roadley said trade would likely prove inconsistent throughout the afternoon as investors analysed other company’s financial results.

“It’s a pretty volatile time where people start to look at numbers rather than at the bigger picture,” she said.

BHP Billiton shares were up 62 cents, or 1.63 per cent, at $38.64, after posting a $US8.1 billion ($A8.96 billion) half year profit.

Rio Tinto was up 92 cents at $70.46, and Fortescue Metals was 11 cents higher at $5.93.

Among other companies to post earnings reports on Tuesday, global packaging giant Amcor was one of the worst performers.

Its shares were down 61 cents, or 5.66 per cent, at $10.17, as its half year profit dropped by 30 per cent.

Coca-Cola Amatil shares were down 71 cents, or 5.99 per cent, at $11.14 after its half year profit dropped by 83 per cent due to writedowns on SPC Ardmona.

Television, magazine and newspaper company Seven West Media’s shares were down seven cents, or three per cent, at $2.12, after it reported it had swung back into the black with a $150 million half year profit.

The big four banks were relatively quiet.

National Australia Bank was up 13 cents at $34.88, Commonwealth Bank was down two cents at $74.33, ANZ was also down two cents at $31.60 and Westpac was five cents weaker at $32.86.

KEY FACTS

* At 1245 on Tuesday, the benchmark S&P/ASX200 index was down 0.8 points, or 0.01 per cent, at 5,382.1 points.

* The broader All Ordinaries index was down 2.7 points, or 0.05 per cent, at 5,392.1 points.

* The March share price index futures contract was up two points at 5,347, with 11,207 contracts traded.

* National turnover was 816.3 million securities worth $2 billion.