Fortescue Metals Group has beaten analyst expectations for iron ore exports and believes it will escape asset writedowns at its half year financial results next month.

The miner indicated that it was still profitable despite depressed iron ore prices, and was seeing its cost base reduce rapidly on the back of the lower Australian dollar and lower oil prices.

Fortescue said its cost of production in the December quarter was 11 per cent below that seen in the September quarter, and amounted to $US41 per wet metric tonne once the cost of shipping, administration and royalties were taken into account.

The economic conditions have allowed Fortescue to lower its cost guidance for the full year by 9 per cent while maintain its full year production and shipping guidance.

Analysts have estimated in recent months that Fortescue would "break-even" at an iron ore price of about $US59 per tonne.

The miner said today it received about $US63 per tonne for its product in the December quarter, implying the business is profitable at current prices.

Despite the iron ore price falling again overnight, Fortescue shares have risen by 10 cents in the wake of the publication of the results to be fetching $2.14

Fortescue shipped 41.1 million tonnes during the December quarter, which was ahead of the 39.7 million tonnes predicted by RBC Capital Markets.

Multiple Australian iron ore producers have flagged impairments of more than $US3 billion in recent weeks, but Fortescue indicated that it may escape the trend.

"Fortescue has undertaken an impairment review at December 31, 2014 which confirmed recoverability of all of its assets at or above the underlying book values," the company said in a statement.

While Fortescue still has $US7.5 billion of net debt, it does not have any repayments due until the 2017 calendar year. The miner paid down another $US500 million of its debt during the December quarter.

Fortescue chief executive Nev Power will address investors and the media later today.