Rio Tinto (NYSE:RIO) and Glencore (OTCPK:GLCNF) (OTCPK:GLNCY) reportedly discussed a potential merger for months at the top level of both companies, in what would be the mining industry's largest-ever deal.

When Glencore Plc proposed a combination with Rio Tinto Group a decade ago, the larger company turned it down after just a few days. News this week that the two spent several months in negotiations in the second half of last year shows how the sands have shifted,

Glencore approached Rio Tinto late last year about combining the two big copper producers but the discussions are no longer active, a person familiar with the matter said. The talks between Rio, the world's No.