UPDATE 1.20pm: Fortescue Metals Group lifted shipments by 8 per cent to a record 28 million tonnes in the December quarter, but issued full-year shipment guidance at the lower end of previous forecasts at about 127 million tonnes.
FMG attributed the lower full-year guidance to bad weather in January, material handling issues affecting the ramp up of ore processing facilities and the change of management at the Christmas Creek ore processing facility.
Total shipments for the half year ending December 31 were 53.9 million tonnes, up 51 per cent on the prior comparable period.
FMG sold its ore for an average $US125 per dry metric tonne over the quarter.
C1 costs were down one per cent to $US32.99 per wet metric tonne, which the company said reflected its continuing focus on operating efficiencies, lower cost Solomon production and a lower Australian dollar.
FMG said sustainable production at 155mtpa remained on track for March, with the ramp up of the Kings ore processing facility and full production from the Chichester hub.
Fortescue, which has aimed to reduce its heavy debt load over the past few months, said it net debt position at the end of December was $US8.6 billion.
"The company continues to have significant flexibility to make voluntary repayments of debt, or refinance prior to maturity," FMG said.
FMG shares closed down seven cents, or 1.32 per cent, at $5.23 in a broadly weaker market.