Global refined nickel demand fell 3 percent in May from the previous month to 170,000 tonnes, while output moderated by 1.4 percent to 167,800 tonnes.
Global nickel mine production continued to rise in May, increasing by 2.3 percent to 178,500 tonnes from the month earlier and up 17 percent compared to January.
Indonesia's mines have ramped up this year after the key global supplier introduced new rules to allow some ore exports in a sweeping policy shift after banning ore exports in 2014.
For the first five months of the year, Indonesian mined nickel supply nearly doubled to 122,000 tonnes from 64,600 during the same period the previous year, boosting primary production in both Indonesia and China.
For the first five months of the year, the global market for refined nickel was in a 27,800 tonne deficit, slightly larger than the 26,700 tonne deficit for the same period of 2016.