The two companies are likely to settle somewhere in the range of $70.0 to $79.0 a tonne and 7.00 US cents to 7.90 US cents a pound for the charges, under the two-year brick contract, up from $63.0 and 6.30 cents for the whole of 2012, said the source, who has direct knowledge of the terms.

The agreement may come by the end of the year, the source added.

Copper treatment and refining charges (TC/RCs) are paid by miners to smelters for converting copper concentrate into refined metal. TC/RC charges typically rise when supply of copper concentrate increases or demand falls in world markets.