Manganese and iron ore miner, OM Holdings' operating profit after tax for the half year ending June 30 has plunged to $10.8 million, down from $96.9 million the previous corresponding period, impacted by sharp falls in global commodity prices.

Manganese and iron ore miner, OM Holdings' operating profit after tax for the half year ending June 30 has plunged to $10.8 million, down from $96.9 million the previous corresponding period, impacted by sharp falls in global commodity prices.