The Australian share market is set to start weaker today after a plunge on Wall Street overnight.

On the Sydney Futures Exchange as of this morning, the September share price index contract slumped 23 points at 4485 points. On Wednesday, the major local indices each ended up about two-thirds of a percentage point.

In economics news, the Australian Office of Financial Management offers on auction $500 million Treasury notes of the October 22, 2010, line.

In companies news, first half financial data are due from Austar United Communications, while Oceanagold reports its second half results.

Caltex Australia managing director Julian Segal will speak about "Fuelling a Brighter Future" before the American Chamber of Commerce in Australia.

The Australia Pacific Aviation Outlook summit carries on in Sydney.

Yesterday, the Australian bourse finished stronger for the fourth successive trading day closing at its highest level in more than a month.

The benchmark S&P/ASX200 index finished 32.5 points or 0.72 per cent up at 4529.9 points. The broader All Ordinaries index added 28.2 points, or 0.62 per cent, to hit 4542.1 points.