LONDON, Oct 18, 2011 (Dow Jones) -- South Korea's Public Procurement Service, a state commodities stockpiling agency, said Tuesday it had bought 200 metric tons of nickel and 1,500 tons of zinc.

The nickel was bought from Glencore International (GLEN.LN) at a premium of $1,020/ton over the London Metal Exchange price, it said.

The zinc was bought from YoungPoong Corp. at a premium of $138/ton.

Both companies must deliver the metal by Oct. 31, the agency said.