Australian stocks closed at their lowest level for six weeks, dragged down by a dive in the iron ore price that hit the miners. It wasn't the only bad news, with the Organisation for Economic Co-operation and Development (OECD) bluntly downgrading Australia's economic prospects. "We seem to be just coming under a hell of a lot of pressure with the OECD downgrades overnight playing a part, global growth as well as Chinese growth not looking so great," CMC Markets sales trader Ben Taylor told AAP. I think people are little bit risk-averse, selling first and asking questions later. The big iron ore miners were all lower, after the price of the commodity fell to seven-month lows of $US112.90 a tonne. BHP Billiton shed 41 cents, or 1.2 per cent, to $34.46, Rio Tinto was down 74 cents, or 1.4 per cent, to $53.96 and higher-cost producer Fortescue Metals Group dived 18 cents, or 5.1 per cent, to $3.35. Banking stocks were mixed, with National Australia Bank down after going ex-dividend, losing $1.23, or 4.0 per cent, to $29.32. ANZ was seven cents weaker at $27.53, Westpac was 14 cents up at $28.86 and Commonwealth Bank lifted 72 cents, or 1.1 per cent, to $67.61. Seven Group Holdings shares were down 17 cents, or 2.2 per cent, to $7.43 after former Woodside boss Don Voelte was named as its new chief executive. He was previously in charge of publishing and broadcasting company Seven West Media, in which Seven Group holds a major stake. At the close on Thursday, the benchmark S&P/ASX200 index was 44 points, or 0.88 per cent, weaker at 4,930.7 points. The broader All Ordinaries index was 42.1 points, or 0.85 per cent, down at 4,917.1. The June share price index futures contract was 39 points weaker at 4,942 with 35,600 contracts traded. The spot price of gold in Sydney finished at $US1407.80 per fine ounce, up $US23.20 from Wednesday's closing level of $US1384.60 per ounce. National turnover was 1.63 billion securities worth $7.39 billion.