The local share market remains under selling pressure at lunchtime in the East, following a muted offshore lead. Japan's credit rating has been cut by Standard and Poor's for the first time since 2002 which is also having an impact on the Asian region.

Mining stocks are under the most pressure, with BHP Billiton (BHP) down 1.2pct to $44.64 and Rio Tinto (RIO) off0.5pct to $85.64. Riversdale Mining (RIV) shares have fallen under RIO's $16 per share takeover offer for the first time since the $3.9 billion bid, after an Indian consortium decided against trumping the offer. RIV is down 2.3pct at lunchtime to $15.87.

Medical equipment maker Resmed (RMD) has reported a 31pct increase in 1H profit due to strong demand for its sleep disorder products. However RMD shares are trading down 2.2pct to $3.17 at lunchtime.

The Australian dollar is worth US98.89c, £0.6225 and €72.14c.

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