BUZZ-Australia's iron ore miners fall as commodity prices tread on a lower curve
** World's biggest iron ore miner BHP Billiton Ltd drops as much as 2.9 pct
** Miners Rio Tinto Ltd and Fortescue Metals Group fall as much as 2.3 pct and 6.6 pct respectively
** Commodities including iron ore, copper, petroleum products and coal traded at multi-year lows
** Prices for BHP's commodities slumped during the 6 months to June, with iron ore dropping 45 pct year-over-year
** BHP's London listed shares fall as much as 5.7 pct on Wednesday
** Fortescue Metals is currently top percentage loser on ASX 300 Metals & Mining Index. The index is down 2.1 pct (Reuters Messaging: anusha.r.thomsonreuters.com@reuters.net)