The share market has closed slightly higher but gave away most of its earlier gains as investors took profits late in the session.
The market stumbled in the afternoon on the back of weakness in the mining and materials sector, OptionsXpress market analyst Ben Le Brun said.
Strength among the major banks helped keep the market in positive territory.
Investors were still testing a market level above 5,400 points, and some were taking profits, especially in iron ore miners, which had enjoyed a strong run upwards, Mr Le Brun said.
"The iron ore miners have been some of the worst performers on the day," Mr Le Brun said.
"That seems to have been what has brought the market unstuck at this stage."
Fortescue Metals dropped 14 cents to $5.84, despite tripling its first half profit to a record $US1.71 billion.
Atlas Iron shed 6.5 cents to $1.08 and Mount Gibson Iron fell 18.5 cents to $1.015.
BHP Billiton was 15 cents lower at $38.74 and Rio Tinto retreated 68 cents to $70.20.
In the energy sector, Woodside Petroleum dropped 13 cents to $38.37 as the oil and gas producer recorded a 41 per cent fall in full year profit.
Among other companies to report earnings, Coles owner Wesfarmers shed 22 cents to $43.18, despite lifting its first half profit by more than 11 per cent.
Online jobs advertiser SEEK soared, adding $2.37, or 18 per cent, to $15.70, after a 65 per cent rise in half year profit.
Suncorp dropped 35 cents to $12.25 after a 4.5 per cent slide in its first half profit to $548 million.
- At the close on Wednesday, the benchmark S&P/ASX200 index was up 15.4 points, or 0.29 per cent, at 5,408.2 points.
- The broader All Ordinaries index was up 13.3 points, or 0.25 per cent, at 5,415.5 points.
- The March share price index futures contract was up 14 points at 5,377 points, with 29,268 contracts traded.
- National turnover was 2.1 billion securities worth $6.02 billion.