A worker walks near conveyer belts loaded with iron ore at the Fortescue Solomon iron ore mine located in the Valley of the Kings, around 400 km (248 miles) south of Port Hedland in the Pilbara region of Western Australia December 2, 2013.
The world's fourth-largest iron ore miner, which has been beset by senior management turnover over the past two years, earlier in the day announced the resignation of its metals division head and co-CEO Fiona Hick.
Fortescue shares, up nearly 2.1% so far this year, fell as much as 6% to A$19.7 by 0200 GMT.
A review of its assets at the company's Iron Bridge project resulted in a pre-tax impairment charge of $1 billion.
The company said rising interest rates and industry-wide inflation had fuelled the asset write-down at its Iron Bridge project, a major plank in the group's growth strategy.
Persons:
Fortescue Solomon, David Gray, Australia's Fortescue, Fiona Hick, Fortescue, Echha Jain, Roushni Nair, Rashmi
Organizations:
REUTERS, Metals, Fortescue Future Industries, Fortescue Energy, Gibson, Phoenix Hydrogen, Thomson
Locations:
Port Hedland, Pilbara, Western Australia, Australia, Bengaluru