Investors wait on words of Bernanke

The resource sector weighed on the market as lower iron ore prices anchored mining stocks.

Fortescue Metals shares were the hardest hit, with the stock scraping a low of $3.65 for the session (down 5 per cent), its lowest since May 2010. Overall, the benchmark S&P/ASX 200 Index lost just 3 points, to 4356.4.

By close of trade, the dollar was at US103.72?, down from US103.74?.

National Australia Bank strategist Emma Lawson said currency traders were behaving cautiously before a speech by US Fed chairman Ben Bernanke tomorrow.

"It has been relatively range-bound for a while now," Ms Lawson said.

Last year Dr Bernanke used the speech to signal the Fed's policy intentions, so some market participants hope for an indication this time that the US will undertake a fresh round of quantitative easing.

Ms Lawson said traders could be left disappointed by the speech. "If Bernanke is less forthcoming than the market expects, then you might, in fact, see the Australian dollar a little bit lower after that event," she said. In the resource sector, BHP Billiton fell 34? to $32.76, while Rio Tinto dropped $1.21 to $50.54.

The Australian oil and gas producer ROC Oil rose 0.5? to 32? after booking a $27.69 million net profit for the first half.

Among the big banks, Commonwealth Bank dropped 10? to $54.31, while Westpac lost 1? to $24.86. ANZ rose 4? to $24.98, and National Australia Bank shed 16? to $25.09.

Among other stocks, Transfield Services was 13.5? lower at $1.915 after the head of the company stepped down, following several profit downgrades.

The engineering outfit WorleyParsons lifted 12? to $26.32 after posting an improved underlying full-year profit despite the impact of uncertain economic conditions and the high dollar.

Mining services group Ausdrill was up 3? at $3.49 after lifting its 2012 net profit by 54 per cent. It forecast more growth this year.

ASX rose 7? to $30.47 after the operator of the Australian sharemarket appointed Reserve Bank board member Heather Ridout as a non-executive director.