Brazil-based Vale has started mining ore at its Goro nickel mining plant located in New Caledonia in the south-west Pacific.
Vale spokesman Cory McPhee said the plant should be up and running by January next year.
The mine is initially expected to generate 20,000t next year as it eventually ramps up to generate 60,000t of nickel per annum.
The Goro mine project, which has been postponed many times during the past year, is estimated to cost roughly $4.3bn compared to an earlier estimate of $3.2bn.
In 2006, Vale purchased the project from Canadian nickel miner Inco.