The sharemarket reversed early gains to finish flat on Tuesday, with a slump in insurer QBE erasing early rises fuelled by record highs on Wall Street overnight.

The benchmark S&P/ASX 200 Index edged down 0.8 points to 5143.6 as QBE led the falls for the second day in a row. The broader All Ordinaries Index slipped 2.2 points to 5146.2.

A monthly measure of business conditions produced by National Australia Bank rose a point to minus three, indicating the operating environment remains lacklustre. NAB's measure of business confidence dipped a point to five.

At the local close, the dollar was buying US91.03¢, down from US91.04¢ at the previous close.

Among the big banks, NAB was unchanged at $33.17, while the rest of the big four were all higher after Bureau of Statistics figures showed the number of home loans approved in October rose 1 per cent to the highest monthly level on record.

Commonwealth Bank added 0.5 per cent to $75.26, while Westpac gained 0.3 per cent to $31.19, and ANZ rose 0.1 per cent to $30.78. The Australian Competition and Consumer Commission has appealed a Federal Court decision to dismiss allegations of price fixing against ANZ.

QBE lost another 9.8 per cent to $10.82 after dumping 22.3 per cent the day before, when it emerged from a trading halt to warn it would suffer a $250 million reported net loss for the year.

Embattled Qantas fell 3 per cent to a record closing low of 96.5¢, after hitting an intra-day record low of 95.5¢.

Rio Tinto subsidiary Energy Resources of Australia lost 11.5 per cent to $1.01, as the government put a ban on processing at its Ranger uranium mine. ERA dumped 12.7 per cent on Monday following a containment breach over the weekend.

Australia's biggest oil producer, Woodside Petroleum, added 0.5 per cent to $37.57, as chief executive Peter Coleman said the company had other development options if a planned $US1.25 billion ($1.37 billion) investment in an Israeli gas field, which has been hit by delays, does not go ahead.

Industrials was the best-performing sector, up 0.7 per cent, as Brambles - adjusted for the Recall spin-off - added 4.9 per cent to $8.86. Document management business Recall Holdings rose to $4.50 after debuting at $4.15.