Vale's head of ferrous and strategy, Peter Poppinga, said overnight the company would not relent from spending close to $US17 billion ($21.5 billion) on iron ore expansion projects, but said it would be prepared to withhold about 30 million tonnes from its higher-cost mines if the weak market persisted.
Rival miners, including outspoken US miner Cliffs, have said Vale can no longer afford its huge capital spending plans given depressed iron ore prices.
Mr Poppinga hinted that any such reductions would be temporary and opportunistic, and Vale would increasingly be focused on profit margins rather than volume growth.
Mr Prendergast said the comments were "significant", particularly in light of BHP's decision last week to defer spending on its iron ore expansions in Western Australia.
"Catching the market by surprise, we expect the announcement is likely to be a further positive catalyst for spot iron ore prices. Particularly given the market's strong reaction last week to BHP's slowing of 20mt of medium-term growth," he said.
Mr Prendergast estimated Vale had a break-even price of $US45 per tonne during the March quarter, and would only reduce that by $US2 per tonne during 2015. Iron ore for shipment to the Chinese port of Qinqdao last traded down 1.7 per cent at $US56.18 a tonne.