The group had achieved cost savings across its aluminium group of around US$200 million a year and had disposed of US$1.9 billion of other non-core assets.
"I'm a pragmatist," Reuters reported Walsh as saying. "It doesn't make sense to give things away just so you can tick the box."
There was "no straightforward solution to improving the performance of the group's aluminium group, Rio Tinto Alcan, which has been hit by slumping global metal prices. The Alcan purchase in 2007 is seen in hindsight by investors as a strategic blunder by Rio, since it occurred just before the global financial crisis, which precipitated the global price slump.
Meanwhile, the Labour Party state-owned enterprises spokesman Clayton Cosgrove said the government's failure to get employment guarantees from Rio in exchange for its $30 million "one-off incentive" payment to keep the smelter in New Zealand showed Ministers were "amateurs."
The new electricity contract returns the smelter to electricity prices similar to those charged under previous contracts, which rolled over at the beginning of the year.
The deal requires the smelter to stay open at least until the end of 2016, but after that, the smelter owners can close the facility on 12 months' notice.
Analysts say the new price probably puts Tiwai Point into the middle of the pack for RTA's aluminium production costs. The New Zealand smelter is capable of achieving premium prices because it is one of only a handful globally making very high purity aluminium.
However, much larger and more energy efficient smelters are appearing, especially in China, leaving the world aluminium market over-supplied with smelting capacity.