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SYDNEY, Sept 1 (Reuters) - Australian shares tumbled to their lowest close in a week on Tuesday after fresh data showed China's manufacturing activity contracted in August, reinforcing worries about the health of Australia's biggest export market.
The widely expected Reserve Bank of Australia's decision not to cut interest rates also contributed to the downbeat mood.
The S&P/ASX 200 index fell 2.1 percent or 110.6 points to 5,096.4 at the close of trade, its lowest finish since Aug. 24. The benchmark has fallen 10 percent since the start of August.
New Zealand's benchmark NZX 50 index finished flat, down 1.3 points to finish the session at 5,655.0. (Reporting by Byron Kaye; Editing by Shri Navaratnam)