The Australian majority owners of the Tiwai Point aluminium smelter, Rio Tinto, have written more than half a billion dollars off the value of the ageing plant, leaving it with a value on its books of just $14.8 million, from $606.9 million previously.
The decision was made in February but has been only disclosed today with the lodging of financial accounts with the New Zealand Companies Office for Rio Tinto Alcan NZ, the subsidiary that owns 79 per cent of the smelter, which has operated near Bluff since 1971.
The smelter's future is under a cloud as Rio seeks to sell a clutch of ageing Australasian aluminium production assets, packaged for sale as Pacific Aluminium, of which Tiwai Point is just one. The company has been seeking since last year to renegotiate its long term electricity contracts with state-owned Meridian Energy.
The 18-year contract, negotiated in 2007, took effect from Jan 1, but falling global aluminium prices since the global financial crisis and a glut of new Chinese production saw the smelter trigger review clauses which could see the plant wind down and close before the end of the decade.
In the latest accounts, for the year to December 31, the smelter made an operating, pre-tax loss of $91.5 million.