Stocks to watch on the Australian stock exchange at noon on Tuesday:

BHP – BHP BILLITON – down 22.5 cents, or 0.76 per cent, at $29.465

RIO – RIO TINTO – down 38 cents, or 0.65 per cent, at $57.67

FMG – FORTESCUE METALS – steady at $2.73

Share in mining stocks are mostly falling despite the iron ore price enjoying a surprise two per cent bounce overnight, rising to $US68.71.

STO – SANTOS – down 22 cents, or 2.6 per cent, at $8.24

WPL – WOODSIDE PETROLEUM – down 41 cents, or one per cent, at $38.17

OSH – OIL SEARCH – down five cents, or 0.63 per cent, at $7.91

ORG – ORIGIN ENERGY – down 16 cents, or 1.35 per cent, at $11.67

Shares in Australia’s oil producers are plunging after crude oil prices fell to a five-year low, amid expectation that there will be lower demand for the fuel because of weaker economic conditions.