Rio Tinto says its Tiwai Point smelter near Invercargill is now running at a profit.

In 2013 the government bailed-out the smelter to the tune of 30 million dollars, in an effort to keep it running.

In its 2014 report, Rio Tinto says it's now profitable because of high product premiums and operational and cost improvements.

However it says the operational uncertainties that brought about the bail-out - still exist.